I've never had to pay fees when a Buyer didn't pay.

I've always been refunded fees on postage when I have given a discount for same.

I have never seen a voucher that says "not a single use" did you misread it?

I see nothing, not a thing that could be called "despicable"

I do not understand "how ebay sellers support number anymore"  what does that mean??

"just minting money out of everything"  What does that mean??

Is English your second language??