Airtel
To activate& deactivate SMS10 service

I want to activate SMS10 service i.e offered me from Airtel.

But If i send Activation request as "SMS10" to 51619

i got reply as " Inalid Requestor Mobile No."

I contact Lots many time to customer care but no one tell me what is problem..

I want that ..

Airtel Find out solution to this..

& i can able to activate & deactivate this service whenever i wants. There is no need to contact customer care again & again..

I am always with Airtel... But Plz I want this service...