Credit Card Charges

I have a balance of €160 on my aib credit card and today I have been charged a purchase finance charge of €7.44. I phoned AIB and they told me it was charged because I hadn't paid off the bill in total. I thought you were only charged if you didnt pay the minimum they request on your bank statement?? I had more on the card but have been paying €100 off each week?? Does anybody know if this is correct?

Generally if you don't pay in full, they charge interest on the full amount (often from the day each purchase was made)

AIB are correct. Customers are entitled to up to 56 days interest free, if the balance is paid in full. Interest is charged from the posting date of the transaction.