Pick n Pays blunder

I have had a very bad experience with Pick n Pay, Mini Mart, Aston Manor, Kempton Park and there is absolutely no resolve in his matter from their side. I went to pay the balance of my Telkom telephone account at Aston Manor. The amount i paid to the cashier Glenda Monoyane on 11.10.2022 at 11:22 am was R4.02 being the balance owing to Telkom. I showed her the coins on the counter being R4.02 and also wrote the amount on the Telkom billing statement and showed her. However this cashier typed in on the cash till R400.02 and pressed enter. Since then Telkom has said i owe them the R400.02 as the manager went behind my back to Telkom accounts department and got the R400.02 reversed back onto my name and account, which is illegial. Since 11.10.2022 Pick n Pay refuses to rectify with Telkom this gross blunder and says i must pay the R400.02 to Telkom. and also sates that i cannot ride on the back of Pick n Pay due to their employees mistake.