Some banks require as much as 3 months (90 days) notice before dropping the holding of a balance in the account. I would go and talk to the branch manager, it is not reasonable (and indeed is not ethical IMHO) to hold funds when the card was cancelled 45 days ago and no new charges have been received by the bank.

Reason with them and if the branch manager won't cooperate go to the Manager of Retail or Credit Operations.