Airtel Friends Prepaid Plan — cannot join a friends group

i have bought a new airtel friends prepaid card and so want to join in a group of three, as given by the network the group password is not valid, though there are three sim cards, viz [protected], [protected] and [protected] that are in the same group and very much working whose password is [protected]. i have called the customer care several times but they have no given me the right solution what so ever. my sim number is [protected].
i hope this complain will serve me some good.