They should have asked for the Club Vistara ID. If you didn't give them your CV ID, they'll generate one for you.
The CV ID linked to your card is in the front of your card, just below your name.
If you want to retain your CV ID and have it linked to your card they'll cancel your card and send you a new one. They cannot change it only on their backend, a new card linked to the correct CV ID has to be generated.
As for activation of Gold Membership I got it as soon as my card was activated. A friend of mine also had the same experience, though his membership took a week to get activated and was asked to settled the joining fee first.