FNB Credit card ***** department failing to refund me fully

*****ulent transactions took place from 28 Feb 2025 to 31 March 2025. Some transactions were duplicates on different dates. Hence the accounts department has refunded me partially and they are refusing to analyze my account. The amount that went out my credit card is R 3 604 but I was refunded R 2 119. The total of R 1 485 is still not refunded when I give them the dates of the transaction that are not yet refunded and amounts to R 1 485, they come back and say these amount have been refunded. For example How can the amount R 200 go out twice on different dates so the total utilized is R400 and refund me once an amount of R200 and then claim that refund of R400 was done.