Hathway — Numerous BB reconnection reminders

I am very much depressed beyond limits of any human, because of the numerous calls and recorded messages i receive from hathway customer care. i.e. more than 50 calls per day sofar 1000 calls in my mobile nos [protected] and [protected]. They remind me to reconnect their Hathway connection which I had for 3 months.
But i shifted my connection to a different service provider and handed over the router too. Though they have not returned my deposit money, I left it. So now i have nothing to do with hathway. But the calls are unstoppable! I have informed the customer care several time more than 500 times patiently telling all executives to delete my no. from their calling list, but they continuously call and which is very frustrating. I am getting BP on seeing their reminder calls and I am shouting at them. I waited for 2 months. No of calls are increasing every day. Don't we have right to choose a different BB provider?. I sent several mails to their customer support and grievence officers. Though they confirmed that they will call, it is not stopping. Please do some thing to stop this hell. Are there any free service advocates will help me to sue Hathway. Thanks. Lilly