non existent service

Worst service ever from a internet supplier, and I should have seen it from the beginning, but chose to give them the benefit of the doubt. When I registered and paid (all online) they never contacted me, eventually I got hold of them and they apologised and fulfilled my order. When the equipment arrived, they did not send sim card...had to wait again.... And then the problems started when sim card arrived - hardly had any service, Everytime you phone them, they want me to restart the modem...as if I have not done it numerous times. I try to caling them now for the last 3 days, and they not answering the phones...I cancelled my debit order and wrote a email to them that I cancel the one sided agreement, where I pay, and they deliver nothing. Let's see if that is going to another issue of them keep taking money from me, as I get absolute no confirmation from them regarding the cancelation