Terrible terrible terrible service

Cell C has given me the outmost worst service to date. They deducted for for much on the wrong date and for every miss premium they will add a R70. I called in to customer service to change the date and paid the outstanding balance for the missed premiums. To date thay haven't allocated that payment that i made to my account or they would say i didn't pay them at all. I've sended through my proof of payments since april 2022 and it's now June 2022 and nothing happened. On my ITC report it shows that im behind with 4 months and been calling customer service and they saying they cant help me, and they will allocate the payment. For almost 4 month they've been allocating my payment. Its having a negative impact on my credit profile. I don't know which way to go anymore, no one can assist me.