I've also found this to be a reason I almost closed up shop. I had about 5 people within a few months claim they did not receive their items. I few I caught out to be a lie and reported to Ebay. But Ebay really do not care for sellers and really protect the buyer.

If you're really having a bad time lately with this happening a lot, I'd be inclined to limit sales strictly to Australia only, with tracking.

That way, you would have proof of delivery.

The way it has worked for me (as a buyer) is when I wanted a refund on an item not at all as described, the seller had to issue me with a postage label. I did not get a refund without returning the goods.

I know it sometimes happens but I think if you respond to disputes with a postage label you should at least get your item back.

But with tracking, they should not be able to claim the item was not received.

I am having trouble understanding what you mean about the sale of the German pen. Even if a customer complained he did not receive it quickly enough, the ad would have had a delivery date range?

I didn't think a customer could open an ebay claim against you till that date had passed.

Or do you mean the customer was just unhappy with the time frame, even though it arrived within the nominated dates. That sometimes happens, you can get unreasonable buyers. It can happen on any sales platform.

I noticed you mentioned 'paid no freight'. Maybe up your prices a bit to ensure your freight costs are covered, you don't want to make a loss.

It can be disheartening when things go wrong but maybe make some tweaks to cover yourself as much as possible with tracking etc and see how things go from there.

Your doing the right thing:

A  specialist store in art supplies

Plenty of low value BIN items

I'd suggest you increase your listings from hundreds to thousands. Where possible lower your prices and when a loss is incurred think of it as getting your money back by paying less tax.  

Another online platform?  Amazon will be no different.  Gumtree?  Facebook marketplace?  Etsy?  Genuinely curious which other platform you feel will be any different.

Rule of thumb, your seller protection kicks in for any INR with tracked shipping, unless it is lost by Auspost in which case you're on the hook, but you can buy extra cover from Auspost.  

No platform is perfect but it pays to know the policies and to implement best practice.  You'll no better elsewhere unless you make that effort.

Maybe at $35 a pop for a biro you could afford to spend an extra couple of bucks for tracked postage.

I don't send anything over about $18 without tracking, and I rarely get INRs.

So, look to your business model and ways to mitigate risk rather than spitting the dummy.

Or, as sugar so succinctly stated, don't slam the door on your way out.

You're hardly a high volume seller, notwithstanding your years of selling, so eBay will not miss you. I am a small seller and seem to have sold (by feedback) about 4 times your volume.

If a customer doesn't receive an item, they are justified in getting a refund.

Please close the door on the way out,

PS.  Dont forget to remove your listings.

At a loss as to how the buyers can win item not received cases if the tracking is being uploaded for each item

In any case, they are not going to read your post here so not sure what your question is for other members 

Do you send items with tracking? That would be proof that your items have been received by buyers