Hathway — Customer Care calling

I have deactivated my Hathway account long back like 6-7 months ago, still, I keep getting calls from their customer service ppl, asking me to renew. I replied to them gently many times asking them to remove my details from their database. I blocked as like 30-40 phone numbers of Hathway customer care. I don't see a point, they call at any point in the day and torture the customer.

I want immediate resolution this issue, and I don't want to get any calls from them