Airtel 3G Dongle not functioning properly

Hi,
I have purchased a 3G DATA Dongle from Airtel Thane,Naupada store on 23rd June 2014.
Customer service executive assured that the same would start in 24 hrs once you give a call to the help line number the same sequence was followed but the activation took nearly 72hrs for activation,meanwhile the online helpline executive were not clear about the reason for the delay and we were tossed around from technical to customer care executive.
We enjoyed the internet connection till 4th of July 2014 but post this date a lot of trouble started.Internet connection was becoming difficult.3G data speed was not available.A complaint was launched at the store on 6th of July which was reluctantly taken by the store as there were few more compliant from my residence area.
I was assured that the complaint would be resolved in 4 working days ,on 7th technical executive called up on the alternative number provided but since the card & dongle was not available with me at the time of call he assured me that he will call in the evening but the call never happened.

Yesterday i called up the helpline once again to receive the shock of life.

First the said call was closed(no confirmation on mail or phone regarding customer satisfaction) and secondly my number was “barred” reason my bill amounting 349 Rs was generated on 4th of July 2014 (due date 24th July 2014) and my credit limit was 300 Rs which was not told to me during purchase I was given 2GB data plan and till 4th July i had consumed only 449 MB of my monthly pack.

Moreever when i confronted the helpline executive Mr Rahul he was rude enough to answer that SMS was sent on my “BARRED” number from our side and you should have your credit limit increased on whihc i told him that i will take the matter to the consumer forum on which he replied that I can go to any forum but i have to pay up first(even though my due date is 25)and then only we can start the number but i explained him that my data paln has not exhausted to this he replied that this the way it works.I demanded i speak to his senior or tema leader both were reluctant to come on line and i was kept on hold for nearly 20 min before the line was disconnected .
My simple question is during the purchase credit limit and its effects that my monthly plan before exhasution would be barred was not explained.
My Bill was generated on 4th of july and store still has 300rs as dongle deposit collected from me still the connection was terminated without the courtesy to give a call or message on the alternate number provided.

Kindly help.

Shailesh Naigade.