Over billed and still not disconnected

Location/place: bangalore

Name of company/service: AIRTEL (LANDLINE)

approx 2 months back i requested that my land line with DSL be downgraded to telephone connection only. I followed this up with additional calls.
This never took place and hence I called AIRTEL to cancel my land line. It seems they have still not cancelled my phone connection. It is also a frustrating experience to talk to air tel customer support.every time you speak to them you get a head ache.