Customer service fails

I did a sim only upgrade on my contract from a pinnicle 10GB to a pinnicle 2GB top up in August 2022 on my contract number ending in 2369. I did this as I could no longer afford my package. Elfonso from Cellc Heiderant assisted me. My new contract was in affect, I loaded my first package of data 50GB for R500. In October I loaded 900minutes on the 21/10 for R199 and 100GB of data for R899. Was billed correctly each time. In december I ran out of airtime so I loaded 900min for R199. Then I receive my account for December in January. R2,108.98. How could this be when I only loaded one voice bundle in December?? I call Cellc, speak to a lady, Nomzamo she tells me that the reason I am paying so much is because I was calling out of bundle, I asked how that is possible when this is a topup contract. She tells me that this is not a topup contract, this is an open line. I have a long discussion with her about this, tell her about the upgrade to the 2GB topup, she says that if I am unhappy with the billing she will ask a supervisor to call me back. AFter 2days no contact received, so I call again, have the same discussion as before, call is cut whilst being transferred to supervisor. Call back, (call 3) am advised supervisor is busy, told I should put my complaint in writing to ***. I put it in writing on the 20th, recieve auto reply. Wait 48 hours, resend email, no reply, resend after 48hours. Called again on the 31st January, speak to a helpful man, he tells me that I should resend the email, he will keep a lookout for it and try to get it resolved. 48hours pass, I hear nothing back. I call again on the 6th Feb, told my email not received, said I should call Cellc Heiderant to hear why my upgrade to 2GB topup was never done, she advises me that this contract was only migrated to a 2GB topup on the 31 January 2023... I call Cellc Heiderant, speak to Elfonso, he says that he put the upgrade to 2GB topup through, it didn't allow him to process topup because there was a balance on my account, so he put the lowest cap on and left it pending. It went through on the 31st January??? even though there was a balance owing... Nonetheless, I signed for a 2GB topup month to month contract. I agree to the monthly premium, I agree to the recurring whatsapp bundle, and I agree to the voice bundle of R199. I do not agree with all the open line phonecalls that you say I called out of bundle. I have had a topup contract with Cellc for 10years + when my airtime is finished I load a bundle, when my data is finished I load a bundle. Never have I been told I called out of bundle. My paperwork supports my claim that I upgraded to a topup contract, at no point did I authorise an open line. My contract has been suspended pending this payment, an invoice which I disagreed to from the moment I received it. Poor poor response from Customer service centre, it is ridiculous, if you aren't on hold for an hour, then you call drops just as you are about to get some resolution. I have put in a cancellation request for this contract and another one I have had for more than 10years. I wish to bring this matter to a close so that I can use my pre paid sim card and hopefully never have to speak to a customer service agent again after this matter is resolved. Besides the failure from customer care to assist me in the matter, I went to the cellc store for assistance on an upgrade, if my request didn't go through, I would expect a phonecall to advise of this, or for another request to be processed on my behalf. I leave there with peace of mind that my request has been dealt with, only to hear that this was an open line up until end Jan... Please can someone get back to me at soonest so that my contact can be amended and I can make payment to get my line resumed again.