It actually has less to do with the vendor, and more to do with the acquiring banks. I hate banks with a passion.
One time had a customer on the line with us asking why he no longer had access. We explained because he had chargedback the transaction. No, no he did not, he assured us.
We called the bank, and found out that he had asked for a chargeback, but it was for another transaction he had problems with, and wanted it corrected. So here we are, my customer service rep, the customer, and the bank on a 3-way call, and the customer is telling the bank to undo the chargeback and give us the money back, and to chargeback the other transaction. And they wouldn't do it. Oh, they applied the chargeback to the other transaction, but the penalty was still applied to us.
The customer apologized to us later, and wanted to pay again, and was even willing to pay the chargeback fee. He simply paid again the normal price, and we swallowed the cost.