Contract migration still not processed!!!

Customer service at Vodacom is getting really bad. I requested a migration more than 2 months ago. I send through the signed qoutation. Expecting that the migration would take place at the end of that same month. Only to discover now that it never took place. I ran out of bundle and received a huge bill for data usage. I requested follow up and requested confirmation that the migration was done a month after my request, with now response from vodacom. I am really unhappy. I want my contract cancelled if Vodacom can't fulfill the side of their deal. If they couldn't process the migration, why not say it. But don't expect customers to pay for service which they are unaware of. Yes it was my responsibility to check with Vodacom that the request was completed, but i am not prepared to follow up and run after vodacom to check that they are doing their jobs. that is not what I signed up for. I am refusing to pay this bill as I have done my part. I will be taking this case up with the ombudsman. This is how companies like vodacom makes money and get away with it.