Airtel — reactivate inactive sim card

Hi my airtel number has been deactivated as i am abroad now. I am travelling in october end so kindly activate my sim card [protected]

I had done recharge few months back but now it has been deactivated automatically.
Kindly tell me the procedure to reactivate as i am using whatsapp in my indian no

Please make sure you don't reissue the sim card to any other person as i don't want to lose this no

Kindly give me a feedback