Cotton on Mall of the North doubled billed on Single purchase- no refund until today

I made a purchase on Cotton on Mall of the North on the 15th of December 2021, they doubled debited on my standardbank account for 1 item R217.50 saying the first purchase was not appearing on their side but on my side the money was taken twice R435 and bank notifications and App was proving that. The cashier advised me not to worry because this happens alot and they will reverse my money.

A week passed without my money reversed, i went back to the shop and they made calls and ended up giving me an authorization number saying i should call the bank because it's reversed on their side, when i call my bank they said I'm not the one who should be communicating with them but cotton on should be, i called the shop and they asked me to wait while they sort it out, it's almost a month now without this resolved, i spent alot of money calling they keep on saying they will get back to me.

I'm so disappointed and tired, i need my money back