Airtel Punjab - Airtel Sim Card Not Working from last 1 Month

Currently, I am residing abroad (Canada) and has been using Airtel Postpaid in International Roaming from last one year but suddenly, My sim card stopped working on ** Dec ****. I called *-* times to the Airtel Customer Care and every time was receiving non satisfactory response. Then I asked my parents in India to go to the airtel Store and ask them about the process for getting the Sim Card Changed and I am residing abroad and can't visit the store personally. The Airtel Store Person asked me to email to nodal officer punjab. I emailed to the nodal officer and they sent me the whole process for getting the sim card changed with Form. I filled and sent the form to the Airtel Store and they asked me *-* times to provide this document and other document and I provided them as I want my sim card to get activated as soon as possible. Now, Its been * weeks since I have completed all the necessary requirements but still my sim card has not been working. When I try to reach the Airtel Store they are not taking my my call and my parents also tried to call the airtel store and same has happened with them. I also emailed to Nodal Officer Punjab and Appellate Authority Punjab as well but they are not responding to my email.