Consumer Redressal

I am a post paid customer to LOOP MOBILE over the last Decade. Never had a problem except for the One I mention here. As a customer, I am assigned a credit of 6500/-. Recently in Dec 2012 I had to travel overseas and got international roaming activated. During the visit, the network suspended its service for 1 days use of billing of over 26,000/-. The network insists & is forceful asking me to pay the billed amount. On my return I called the network, lodged complaint including the Nodal Officer for this unwarranted billing & asked them to look into the same. I made frequent visits & calls to the gallery, customer care to discuss get the issue resolved. Relationship manager confirmed meeting at my place to understand my grievance but never came inspite of confirming. I re-lodged my complaint again but to no effect. After months of harassment from collections cum recovery department I have been sent an advocates notice to pay their decided amount. Please advice & help.