Incorrect termination of contract

I had two contracts with Cell C, one of the two contracts was expiring in July. I sent cell c an email to terminate the contract that was ending this year, which I was not sure which one it was and I was specific about that . I received an email back to say the contract would stop and the last bill would be in June 2017. I received an sums a few days later, and I was told my contract was ending in July and I should contact cell c to cancel that contract. I sent an email, and received one back to say my request has been processed and my contract will end in July 2017. So now apparently somebody at cell c did not bother to check the first time around which contract it was that was ending this year, and now I am liable for cancellation fee of R2700. I called cell c to get a settlement amount because I was told that they know nothing about the R2700 and the settlement amount should be R993 and R139 for both numbers which I couldn't understand as one of my contracts ended in July 2017. I paid those two amounts and now I am getting calls that I owe the R1700 and each and overtime I speak to someone trying to resolve the problem, I am told they know nothing about such an amount and I should pay one last amount and that would be the end of it with cell c!!! Now I am getting phone calls and sms's saying i owe them and i have to each and every time explain the mistakes of cell c employees!!!! why do i now have to take accountability for your employees' foolishness, why cant somebody come up with a resolution that we can all agree to??? why am i being treated as though i do not know what i am talking about because of your ****** mistakes!!!????? i am sick and tired of having to go through all of this with cell c!!! you people need to fix this mistake, come to me when you have an agreement i can also agree to or we will have to take matters further!!! I WILL ADVISE WHOEVER IS READING THIS, NEVER TO TAKE CELL C CONTRACTS!! you people just care about taking people's monies and not care about the after sales well-being of your customers!!!!!