Airtel — airtel prepaid sim suddenly not working

Address:	Chennai, Tamil Nadu, 600096
Website:	Www.airtel.in

I am using this airtel sim for almost a decade. Just a couple of years back, i replaced it 4g sim and using the services. Without any prior intimation, they stopped the service to my sim. When i checked my nearest airtel store (Okkiyam thoraipakkam store, chennai), they told me that my sim is still active but i need to get a duplicate sim to continue the services. But they told they are out of stock of sims and so they can’t provide me a new one. My sim was not working from friday (2/2/18) and they still say stock not available. They ask me check in adyar or athiruvanmiyur airtel store. Due to my work timings, i am not be able to travel to those stores. Since my number is not reachable, i am facing lots of trouble, both personally as well as professionally. As a airtel showroom, they ought to have new sims handy. I am wondering why they are not refilled with new sims. Please help me in resolving this issue at the earliest.