Airtel Prepaid — Misleading About new Plan.

I am using airtel prepaid no. since last year oct.
In last month on 28 oct 09 I have recharge Rs.70 for lower the STD call rate in which All std no. other than Airtel cab be call at 0.60 paise and on Airtel it charges 0.50 paise.
This month nov'09 I have recvd call from Airtel customer care that recharge with Rs43 for lifetime validity and on 21st nov 09 I have made recharge of same but at same time they Stop my last months facility that is Rs.70 of lower std call rates. Then on 23rd nov 09 I call customer care and ask for same .He reply me that i[censored] change plan then existing plan will be stop but I told him that u must tell me at the time of giving call for rs43 plan u were hide this thing from me and I had lost my plan.
so this services r made in such manner that i[censored] have to increase validity u have bare a LOSS.
But they should think I m increasing my validity that means I want ur services for further period that I want to remain ur customer but They do not bother about existing customers.They simply repling sorry we cant help u in this matter.This things r not good as per my view.