Airtel — Wrong commitment made

Address:	New Delhi, Delhi, 110070
Website:	www.airtel.in

I am using Airtel number-[protected] from last 2 years and was happy with the services but last week of october i recieved a call from Airtel stating that There is an offer for your number if you change your plan to 599 you can avail the mentioned benefits as:1040 STD mins, 360 local mins and 1040 3G benefits after consumption of which unlimited 2G will be given.I informed them that i am shifting to Delhi next week so will i be able to use these benefits there and what about the roaming charges? To this question they replied that this is National MNP offer for you and you can take these benefits in Delhi as well.Then they sent their associate to my home for collecting documents and changed the plan. Now i am in Delhi and whatever the commitment was made is FAke.I contacted them via there Call center, showroom and email but they are now telling me you are not eligible for this offer and i need to port this number again and take 799plan.No other option is left.I cannot even go to my earlier plan of JK. I dont know what to do.I cant throw this no.out because i have given this to all my contacts but i cannot even bear such charges.