Airtel — sim block jk

I lost my mobile having airtel number [protected]. I am from. J&k and during my visit to home i lost my mobile. I was expecting it to be misplaced but now i feel like it's stolen. I am back to chandigarh and want to block sim from here as i can't go back home. I called customer care number and they are saying i have to go back to jk for sim blocking. They gave me two numbers for jk airtel both of them are not working. Please help me block the number as it can cause security related problems.
Thanks