Investigation on account will take a month or more

Good day, I went to pay my account on the 1 of December to find that a purchase amount R2269.76 @3:21PM was made on my account on 24 of November 2015 at Mr Price Mdantsane(Eastern Cape according to the manager at Westgate Gauteng). I was however sitting at work on this date in Gauteng and with my MRP card at that time so this is impossible. The lady at the tellers help me in a very good manner phoning head offices and arrange for the card to be stopped and ask me to bring an AFFIDAVIT, which I did and she faxed it through. Today I phoned to find out what is happening and the lady answering informed me that it is only a week?? they behind as there are 100+ cases like this to be sorted out. She stated that it will take a month or more to sort it out. REALLY!!!! deeply ANNOYED right about now as they are interfering with my Christmas shopping!! They need to sort this matter out quicker. It is not my problem. I want answers as to HOW someone has purchased things with my card and why wasn't signatures confirmed!!!! I will not pay my account again before this is sorted and corrected. The mere answer that there is 100+ cases like this