Infuriating Cell C services and billing

Infuriating Cell C Good day, my name is Winston and I am turning to social platforms out of desperation with the service of Cell C regarding my account. In 2019 I got a SIM only data plan for R289 per month for 50GB on a 24 month contract. I had no complaints about the plan and was happy with it. In March 2021 I was contacted to upgrade as the contract was nearing its end. I was offered the Home Connecta LTE plan for R199 for 50GB day and 50GB night. I was very happy with this upgrade and for the first two months or so everything was going well, I was billed accordingly. On May 5th I double checked my account on the app and per SMS and I was shown a balance of R0.00. However the trouble started on the 10th of May when they tried to debit my account again at which time the app reflected a due balance of R780. I was called again by a consultant who proceeded to tell me that they now offer a router for an additional R69, I agreed to this and was told by the consultant that I was billed the R700 due to the fact that on Cell C’s side it showed that I had not upgraded. Still not sure where R700 comes from but… The consultant promised to sort it out and call me back in 5 min. Never called. So far I have called Cell C many times and they have called me many times also, got ref numbers, were made promises, case escalated many times but NO RESOLUTION as yet. Once a week I am called by an agent telling me that I need to upgrade and the whole story repeats its self. My account is sky rocketing stands at over R2000. What am I to do? Is this the way Cell C treats loyal customers? Should I seek legal assistance and contact the Ombudsman? What must I do? This is very frustrating and ridiculous.