Extremely unhappy with billing and accounts as well as negligent customer services with invalid information

I have had the most horrific experiences with C cell upon taking out my 2 contracts and have had nothing but problems. I have had numerous complaints calls and such lack of assistance and negligent uninformed consultants handle my account. To start off with I had to wait an extra week to receive my cellphone on contract because a cell c consultant messed up my delivery address after I changed it. I then had to wait an extra 4 days before I received my wifi router. Once I received it, I was not advised to set up a data usage limit but I did on my phone. I then proceeded to set one on my wifi 3 days later after the weekend which i was told I had to have a limit of R50 I then called back and said I could not afford to pay any extra and the consultant set a limit so that I could not be billed anymore than my contract of R129.99 per month this was on + - 10th july. I asked the consultant before hanging up how much I would be billed he explained the R129.99 for the wifi and the R199.99 for the phone in the month of August, but that I WOULD NOT be billed in july, Just the per amount of days. I asked him then per days if i had R600 in my account at the end of august if that would be correctly saf to cover july and august fees he then claimed that it would be considerably less because per amount of days ion july and would not add up to double as such, but rather just a bit over my monthly contract amount-and that at that time he could not tell me the exact amount. I noticed data had been coming off my phone and that my wifi wasnt working, I also wanted to change my debit date, so called in today and I have been INJUSTLY charged R3000 FOR MY WIFI ! which was said to have been used during the 3days before I capped my wifi! I waited forever to speak to management who could not assist but simply kept wanting to high flag my request in billing. I then calmed down and called back to ask a consultant for an itemised data invoice for both contracts and I never received an Itemised invoice as promised! just simply an invoice with the amount of R206 due on the phone contract and R3415.32 DUE ON THE WIFI! on the invoice statement it also only says for the month of 1 -25 august and not july which is there fore impossible! Because also if that is the case I had definately set my limit prior.! I am absolutely besides myself and extremely worried about being blacklisted. I urgently need assistance as I cannot be billed any more than what I took the contract out for! I had also numerous amounts of times prior checked on my spending with a consultant to verify that my data had run out and I wasn't being billed extra. The manager that I spoke to offered very little help and wanted to avert the problems to billing and blaming me saying that she could send a list with where my data had gone to. I absolutely refuse to pay for the mistake of customer care and negligence when I literally cant afford it and am now in an absolute state of not knowing what to do. Please urgently assist me.