Worst Cell Service provider ever

This company is the worst ever cell service provider and they are also theives in that they have ****** over the years from me as a client (on contract and pre-paid) the amount of R699 300,00 (that is six thousand nine hundred and nine three hundred thousand rand) from me. That is over a period of more than twenty years and I been trying to get my money back and they have the nerve to claim money from me as I have done all the correct processes to terminate my contracts with them.