Nobody answers and shocking service

I as well as others have been a iBurst subscriber for many years. I live in Green Point, Cape Town and have a very poor signal. My service provder who is Vox Telcom try their best to help me get connected but for the last three days i cannot connect to the internet and when you try phone iburst they never answer their phones and I feel that its not worth continuing my service and will be cancelling my contract at the end of the month.