I have been using Tata Indicom Walky for about 8 months. Bill plan is postpaid and very good plan costing Rs 145-200 per month. Network is really great. Easy to dial, no disturbances. Customer Service is good. We get regular updates on bills and dues, Offers regarding the plans.
As such I am not having any issues since I have setup my landline. So I didn’t needed to call customer support. Charges and billing is very good, cheap and best.