Airtel — messages not received

Address:	Mumbai City, Maharashtra, 400078
Website:	airtel.in

Few days before suddenly my sim was not working and i unable to received calls and messages. I submit my compliant online through airtel portal but complaint still unresolved. I visit airtel store where they told me to change sim card and for that they charge rs. 25/-. I changed my sim. I am able to received calls but message service is still not working. I am not able to receive message since last 4 days. Worst service from airtel.