Airtel — all channels are busy

Address: 560097

Anytime I place a local or std call, it says All channels are busy. I've been trying for a week now. I don't know why it offers free calls and doesn't allow to make a single call. I am sure the customer care has dealt with this issue earlier but they still pretend not to know about it. They just know to ask us to restart our phone ...like it will fix their network issues.