My local chemist store changed their no from airtel to mtnl few months back, i asked them why they changed the no, they said they don't trust airtel, they used to always get charged for calls they never made and now they are happy after moving to mtnl.I recently got Rs499 rental plan from retention dept where i get Rs 450 calls free, when i got my bill i was charged the rental + the calls i made, i did not get any discount, registered a complaint, got call back from their billing dept rep who told me that free calls were only for airtel to airtel and calls to other networks were charged normally, told retention to disconnect the line and they told me that free calls were for all networks and not just airtel to airtel and i have now received refund for the extra amount i was charged, can't say if the billing dept guy who called me made a genuine mistake or purposely lied/misled me because its very difficult to trust airtel these days .