Disappointing service

I am extremely disappointed and frustrated with the service I have received with the company!!!! I had 3 contracts with them the 2 were handled well and closed March 2023, 1 contract was escalated and handed over to VVM I deposited money to the Cell C account unaware that there’s a new bank account linked to VVM…I was then told that there’s interest added to my account due to none payment. I then explain that money was deposited to Cell C account and I asked for payment allocation since last year December until today that payment has not been allocated!!!! As we speak I’m getting calls stating interest has been added because both CellC and VVM have failed allocating payment I’ve sent POP countless times but none have came through with a solution. CAN SOMEONE HELP WITH MATTER AT HAND!!!! This is really frustrating