petition approved got docs not stamped can employer revoke it?

my premium processed petition was approved in april. my employer sent me documents without client letter. i asked him for client letter and pointed to clients who are willing ot give me job. but he not proceeding with then and also asking me not to go for interview until he says. Even i cant go to interview without client letter and sow.

i couldnt understand if he is trying to revoke my petition.

  1. can i transfer that with new employer after he revokes it?

  2. can any employer apply for a new petition for this year as the cap is exempted?

  3. will employers revoke approved petiton just to get their money back?