Disconnection of Services even after paying the amount in advance by cash

I have paid three months advance by cash to the airtel sales agent.But when we are calling customer care they are telling everytime it is not updated in our system and disconnecting the airtel internet services.When we call them they connect it for an hour and then again they will disconnect it.Same thing is going on from past 15 days.Even after paying the amount we are not getting the connection.

Thanks,
Pooja Garg