Airtel Prepaid
Roaming problem

I tried to contact one of the coustmer service in airtel gujrat but i can't any reply yet so i want to know how can i topup my accoutn when i am outside the country. i am at london last 1 year i want to topup my account and activate my roaming as well so please forword my complaint to airtel gujrat.

My mobile no : 00919898118884