I understand your frustration (I have 9 UPI cases open at the moment - one buyer purchases $200 worth of items then disappeared off the face of the planet 
and I've also been on the receiving end of an email from an angry buyer for opening a UPI case after over a week from purchase and no replies to my query).
In saying that, if you're referring to the note on pages that has a link to 'learn how' to handle problems with customers etc, I think that's just a default thing that is shown to every seller after opening a case, so it's not to be taken personally.
TBH, I find the best way to deal with these situations, when sending customers a message, is to limit what you say to a simply enquiry - I don't mean to suggest it's necessary to walk on eggshells around them, but I try to avoid anything that could put someone on the defensive, simply because I have no idea why they BIN'ed an item and didn't pay (there may well be some legitimate, understandable reason), but what happens once I'm at the point where I have to recover my fees is - to put it bluntly - nothing to do with me and not my problem.
So, I have a message I copy / paste after a few days, and it just says I'm contacting them as payment hasn't been receieved yet, if they're able to get in touch and let me know how they'd like to proceed with the transaction, that'd be great, and I also mention if they have paid, could they provide some further information so I may be able to investigate what could have caused the error or oversight - if they don't respond or pay, I feel there's nothing in that for them to get angry at me about.
PS I responded to the buyer who was angry at me for opening the UPI case by telling them in no uncertain terms that while they may know why they haven't paid, I can only base my decisions on the information I have, and all the information I had was that my item sold, the buyer didn't pay and didn't respond to messages. Never heard from them again.
@2106greencat wrote:Just to play devils advocate - One has also asked why this buyer did not pay at point of sale?
Because they are not required to do so...they have 8 days.....Seller can open dispute on day 4 and close on day 8.
Many buyers pay immediately if they can - I am one of them, but if I saw an auction ending on a day or two before my pay was due to go in to my bank it would not stop me from bidding, knowing that I had time to pay within the specified time.
Just to add to that, I don't sell clothing anymore (I used to for a couple of years), and like you (OP) I mostly had one-off items with just a few mutliple-quantity listings. At the time, I allowed 7 days for payment, even after the UPI dispute process was shortened from 7 to 4 days, primarily because my items were one-off and wanted to allow for people who really wanted something enough to secure it (by BIN'ing it), but may not be able to pay straight away, which would happen every so often. And, because that was stated in my listings, both the buyer and I had a clear, specified time-frame for post-sale processes (in other words, I let buyers know upfront what they could expect from me, rather than have them make assumptions based on eBay's guidelines / timeframes, or experiences with other sellers - the ones that actually read my terms, anyway 
).
These days I mostly sell multiple-quanity BINs so there's less instances of a buyer being concerned they'll miss out on an item if they don't buy now, and have shortened the payment time-frame to 5 days (as a matter of practicality, since I can't even open the UPI until after 4).
But while I can understand people wanting to buy an item and pay when they have the cash, especially if there's only one available, I'll never understand it when there's no extenuating circumstances at all (like revised invoices, waiting for other items etc). I had one buyer BIN a $5 item that I always have at least 30 of in stock, didn't pay for week, then when they responded to my query (exactly 2 minutes after I sent it) they let me know their nan had just died that day (the day of the query, 6 days after the sale) and would have to pay the following week... I replied that I was sorry for their loss, but under the circumstances I felt the best thing to do was release them from their obligation to pay and initiate the process to cancel the transaction, then opened the UPI dispute. 5 minutes later, they paid (wasn't expecting them to, or particularly wanting them to, but nan was - presumably - alive and well at the time of purchase, so blowed if I know what happened after they clicked BIN o.O )
@lentradirect wrote:
@digital*ghost wrote:
So, I have a message I copy / paste after a few days, and it just says I'm contacting them as payment hasn't been receieved yet, if they're able to get in touch and let me know how they'd like to proceed with the transaction, that'd be great, and I also mention if they have paid, could they provide some further information so I may be able to investigate what could have caused the error or oversight - if they don't respond or pay, I feel there's nothing in that for them to get angry at me about.
OP this is absolutely the best advice we have taken . Thanks DG never had any issues with UPI after adopting this procedure .
That's awesome 
I'm really glad to know it's helped, thanks ^_^.
