custom airtel broadband plans for existing customers

Hi frineds, On this march 20, I took a connection from airtel broadband in Bangalore city with the plan 899 for 15GB @ 4mbps with free wi-fi router. And I paid a total of 600 rs to their sales man,And he told me that the connection will be activated within 3 days. But upto yesterday,I didnt get any calls from Airtel and I think I am cheated by them.
But yesterday morning,they called me and informed me that such an offer is not available in my place.So I demanded for refund of my money and at that time they told me that it is not refundable,instead of that they could provide me a plan of 1199 for 25GB @ 4mbps. And they also added that they could provide me the same 899 plan which I requested after a month.Because 899 plan is not available for new customers.So I agreed with them..
All I need to know that whether their promise is trustworthy or not...
Is anyone here who experienced such a migration in their plan within one month of a new connection..
Please help me, Thanks in advance.

Whatever you do, have airtel email you details of what they're willing to offer, to maintain a record of sorts; in case things go bad.

Airtel rates and plans are so that its 20% more than the market value. And a little bit of cheating in landline plans so better avoid.. unless you are an airtel fan.