Cell C Customer Care is disaster

I have agreed to a contract with Cell C in July 2022. Two SIM cards were delivered instead of one. When I enquire about the second SIM card, I was told that it was a free 30GB as a token of appreciation for signing a new contract. I'm currently getting billed for 2x Sim cards. I was promised that I will pay a pro rata from R599,00 monthly subscription at the end of July but to my surprise I was debited an amount of R1395.00. Efforts to resolve the matter with Cell C came to zero. I was asked to forward a police affidavit, bank statement and my certified Id copy so that their ***** department can look into my complaint but until today nothing came out of it. I stopped paying until my problem is resolved but I'm still aware that it is impacting negatively on my credit rating. I even suggested that we cancel the contract before the three-month grace period lapse but I'm still waiting for feedback