Livpure — Harassment and legal notice

I got an ro installed from this company in August 2020. Because the quality of water was bad enough to make me ill and and also i had to move to new place in January 2021 i asked them to cancel subscription and take their ro back. For days they didn't respond. All i use to get was 'madam we will get back to you soon' and for days no one called back. Seemed they didn't have enough people or competent people to handle the issues. Then i moved to a new place. For the next four five months there was no call nothing from this company and then sometime around june their personnel started calling me for like 10 times a day for the ro ..i somehow managed to talk to my old landlord (who was reluctant enough) and set a date to get the ro installed .. no one again responded to calls. Now again suddenly after an year later i get a legal notice like a lot of their other customers demanding 15k for the ro and 8k for the dues. To this i tried calling the customer care again n number of times and again there was no response. Only when i took the matter to Twitter these people responded and i got a call. The person i had a conversation with said that i need to either handover the ro(as if i am moving around with it) or i need to pay money. Now how can i handover the ro ..i don't even live at the place anymore ..i tried contacting the old landlord again but to no use. Their representative asked me 'madam if we didn't respond to your calls why didn't you send us email' ..like really? Send email because you didn't respond to calls? They are doing this with lotsof customers it seems. Harassed me for almost an year, provided bad service, didn't respond to calls ..all this just so that they can send a legal notice an year later? This is plain extortion. Please anyone help.