Problem with a purchase shown on your statement: Credit card

I went on a trip and used my Barclay credit card. Upon returning back to my hotel, I noticed a transaction with a merchant on my account that I did not approve. I quickly contacted Barclay and informed them of the situation. They temporarily credited my account $10.00 and sent me a new credit card. After a few days Barclay contacted me to ask me if I still had my credit card in my possession and I told them yes. The following day they reversed the temporary credit. I told them again this charge for $10.00 was not valid. They told me they were reversing the credit because the card 's chip technology had been used. I explained to them that I handed the merchant my card to process a transaction for $75.00 and they not only processed that but then proceeded to process an additional $10.00 transaction without my knowledge that I was disputing. I did not approve a $10.00 transaction. I explained this to Barclay and they still refused to help me. Instead rewarded a business that scams consumers.