MWEB bad internet service provider

I have been having intermittent internet service for a few months now ...but my payments are always ontime I spoke to sales and they confirmed with me that it was a good idea to change network .....( I am with openserve for 4 years .).... I agree to go over to vumatel ... Unfortunately the internet service remained the same so I am obviously aware that this I now the Isp .... I was told I can cancel at anytime if I am not happy at no cost .....however mweb is now telling me I need to pay a cancellation fee .... Not only did they not cancel openserve on the agree date but they also debited me for 2 networks to the same address....I called in which is a costly exercise because there is always a period that you need to wait ...so U end up spending a few hundred on airtime ....but I get through an they realise that they made. Messup ..... I eventually reversed the debits because I said I want to cancel an move to another isp .... They have terminated my service but have a bill of over R2500 ...the funny part is that m an service wasn't even activated as it should have been on the 1st April .... They now seem to holding me hostage as they have not released my line so that I can move to another isp a requested . Should I go to icasa with this query or will mweb sort this out .