Horrible experience

I have had a horrible experience the past 3 months starting from where a double deduction was made to my account and when requested to correct this I was sent from pillar to post. The following month the deduction was 3 x the owed balance. Various frustrating phonecalls and promises to correct this has still not been done and now I received a statement stating I owe 4 times the amount. I've been a loyal customer with Cell C for many years since the beginning of Cell C and this is the treatment I receive. Totally unacceptable and impossible to get hold of someone via the call centre or at a branch that honours their promises or sort out the mess.