I have had a problem with click and send parcel today, the buyer only paid the postage, without the $3 for signature, which was the only option I allow.  I just assume it was eBay that gave the buyer the wrong amount; they paid before I got the chance to send an invoice. Sounds like some glitch.  huaershop   you need to set your setting such a way that people cannot change the postage amount.

Why do you charge $3 for signature, when it costs $1? I certainly wouldn't pay $3 for the signature option on C&S.Why do you not include it in the item price or handling cost if you don't offer any other option?