Contract cancellation

There are more then three weeks no Internet at our home untill today(27/11/2018), we aksed two times technical come for repairs but no of them fixed the Internet problem, there are still no Internet in our home caused us a lot of trouble, we can't study and work at home. We've made our troubles clear on the phone and online form several times, but VOO didn't want to solve our problems, In this case, we have to stop VOO Internet service, we asked to cancel our VOO Internet contract. but VOO always don't want and not to cancel our contract and the wrong bill of November.