TFG ****med me on the account that I have with them.

Just a month into opening and using a TFG account I've already been de*****ed of R649, and nobody at TFG is willing to assist me trace this transaction that is only known by them as TFG, the store that is said to be the one that processed the purchase does not have a working contact number, all the numbers available on the internet don't go through.

I have a two months old TFG account, I use a Markham card. Last month (May) I made my last purchase on the account, and my closing balance after the purchase was less than R900, with a credit of R103. Fast forward to June 25 when I went to pay my monthly installment, I paid R100, and the receipt brings it to my attention that instead of getting the balance reduced by R100, the balance was actually up by more than R500, from R800 to R1308. I then emailed TFG on all their emails, I never got any response, I then decided to call their Cape Town call Centre today (28 June), the agent who spoke to me said on their side of the system it shows that I owe R1308 because I made a R649 purchase on the 22nd of June. On this very day I was at work, I never went to any store. When I ask which store this purchase was made from, she says it was Markham Westgate Mall. I then said I never made such a purchase, she said I'd need to call the store to ask what went down, and the store's number doesn't go through. Strangely, I have a R952 credit limit, and when I made my last purchase I had R103 buying power left, but when this mysterious purchase happened, something worth R649 was bought, how? How does the account suddenly manage to buy for R649, about R500 above its limit?