Do I need to pay this charge?

I was touring some islands in Thailand earlier this year and ended up being charged by a merchant a fee for using a credit card to pay. This was a roughly $4,000 charge on my Capital One credit card, and the charge was in Thai Baht. Capital One let it go through but shortly after, I got an email from them stating that "The merchant did not pay the assessment fee for the transaction" and I now have to pay a fee of $212.94. I was able to get Capital One to drop this fee twice before because I was able to talk to the merchant and get them to agree to pay the assessment fee, but the manager at this hotel is not agreeing. He is saying that their bank is saying that this is not the merchant's responsibility. The merchant is saying that they are probably going to just end up deleting the charge and will just have to take the loss. I really don't want to pay this assessment fee, because I don't want a merchant to be able to charge me for using a credit card. I have roughly 4 months to pay this fee. I really don't want to pay it, and was wondering if anyone has had a similar issue?