BT won’t stop cancelling our broadband contract

We’ve assured them we still want it, but it’s happened three timesSince we started our broadband with BT in June 2017, they have three times cancelled our service despite us assuring them we still wanted it. And each time they did this, they tried to bill us for the remaining amount of our contracts. This first started when neighbours moved in next door and we started receiving “somebody wants to take over your line” messages. After this, we were set up on an 18-month con