unauthorised transactions

I have been getting declined foreign transactions (457869*075 6) on my account that have been taking R8.00 away. I recently went to the FNB branch in ferndale on republic and was told that it was a purchase i made, which had international charges linked to it. However, my sister has also made the same purchases and she has had no unauthorised transactions coming against her account (different bank) . I then found 2 other people on Hello Peter who had the exact same problem as me. They have stated that it is a **** and that FNB has allowed it to come against their accounts and also mine. I am hoping that someone from FNB can help me resolve this problem. If not, then I will have to consider changing to a new bank as this is not acceptable.