Supersonic sucks

My business relocated on Monday. I gave supersonic at least a months notice. I told them I already had a fibre connection at my new premises and that the fibre network was unchanged. All they had to do was activate the line. Their communication system sucks. You can no longer get hold of them by a WhatsApp call, they call yo back after 24 hours when you maybe elsewhere, doing something important but it seem that there is a technical problem with their WhatsApp as it does ring. I have been without internet for 48 hours and feel I have to change my service provider but I can’t get hold of supersonic to cancel them’!!