Refusing to return money mistakenly transferred into Cell C account via EFT

I am extremely disappointed in Cell C. A month ago I tried to recharge R300 of airtime via internet banking and it inadvertently went into a Cell C bill-paying account. I flagged it immediately by going into the Cape Town, Kenilworth Centgre branch who said they needed a statement of the transaction from the bank. I gave them that, but after I followed it up again a few days later, I dealt with somebody else who, they only now tell me, is a trainee. so nothing further was done. They then wanted a full bank statement, so I went back to the bank and got that for them and they emailed it off to their representative. I've been in and out of that shop countless times, wasted petrol money, called them a number of times from PE when I had to go there for a few days and have basically dealt with whoever has been available, which means every single staff member in the shop. I keep on being told it is being dealt with and somebody will call me back, but nobody ever has until today. I've now been informed that it's the bank's problem and they need too escalate it as they can't trace it. However, when I went to the bank, they printed off all the details for tracing purposes and said that Cell C need to take ownership as they have access to these details and they would have set up the account. The bank also indicated that they can recall the funds, but that it would cost me R290 leaving me only R10 of the original amount which Cell C is sitting on and refuses to return to me, which clearly defeats the purpose. I am really angry at Cell C passing the buck like this (for a month!) when they have all the necessary information to return the money to my bank account. They should never have let a trainee handle it unless being supervised - if I had known, I would have asked for someone else. As they haven't done anything constructive for a month, I was advised today to write a review on Hello Peter. I am really sick and tired of being fobbed off by Cell C Kenilworth branch telling me that it is being dealt with when it isn't. A month of this is just gross inefficiency!