Hathway — Harassing calls for hathway broadband

I have disconnected my hathway broadband from past two yrs and still I'm receiving call from hathway and forcing me to rejoin hathway amd harrassing me by calling evry alternative day for this and when i told them to put me on DnD they gave fake assurance that it is done will not receive calls but still receiving calls and also when i told advisor that I'll complain about this they told me that do whatever you want and that was unmannered and unprofessional way and not just this they also say that no one will take action against them is this the way company should treat a customer and plus the advisor has the audacity to say that do whatever you want need help by the law