Hathway — Hathway Broadband - Stop telemarketing calls and sms to my number

I have disconnected hathway broadband connection because of relocation. I called their customer care team and also mailed them to stop sending promotional calls and SMS to my mobile number. But they linked my mobile number to a new broadband connection with my disconnected broadband account number. Till now I'm receiving promotional calls and SMS. I tried using DND but then also I'm getting their calls and SMS.