I have experienced this. Merchants say that they have to pay rent for the EDC machine and/or processing fee. More than the customer, it is merchants who put their foot down, demand & finally win.
Every credit card (CC) holder should be aware of CHARGE BACK; the only protection for customers.
What is 'charge back' and how does it work?
If a customer is unhappy with a purchase thru CC, s/he can demand for 'charge back' so that bank will reverse the amount billed on CC. That is, bank will cancel that purchase & will not pay the amount to merchant. Net result is customer need not pay for that faulty product or unsatisfactory purchase. The charge back can be claimed within 180 days of the purchase date. Does any bank educate customers of this fact?
When the MOTO (Mail Order / Telephone Order; a.k.a MOPO-Mail or Phone Order) was in practice without the CVV number, a merchant charged my brother for an unwanted holiday package. After noticing the charge in the statement we demanded the bank for charge back successfully.
Next time when merchants demand a 2% transaction fee to be paid by me, I would like to ask them to bill it separately and collect a receipt for the same. Later go for charge back.
Last but not least, I do not think banks are bothered as long as they get the transaction fee; whether it is paid by the merchant or the customer.