Airtel — being harassed by multiple calls after raising disconnection request

Address:

122001

I have been using airtel broadband for around 2.5 year, in past one year the speed quality (2mbps) has suffered and i have raised multiple requests to rectify it which went in vain. Since last one month Airtel is promoting its new plan in my ares (100 mbps), when i called customer care they said such speed upgradation is not reflected and cant be entertained. I have waited 1 month for them to upgrade the existing plan which never happened. although my neighbours has enrolled to new plan and getting 100mbps speed. Now that i am completely disappointed and have raised disconnection request Airtel is Harassing me by calling every day with some proposition. They are brazen enough to now send a technician to my house without my knowledge and permission. Is there a way i can sue this company for cheating me of my money and trust when i patiently waited for them to upgrade their services and my plan and now harassing me when i have very clearly raised disconnection request.