So, bank account for annual jolly boys weekend away set up years ago into which £35 per month paid in by standing order. The other lads also paid into the account.

The account was closed last year but I never stopped the standing order…duh!

How do I get the money back. Lad has a bank book but Halifax appear not to be able to tell him how much is in there and when the account was supposedly closed they sent him a cheque for balance but payable into the closed account….

Yup they can, they just need to look harder.
Ask them about reclaims process, they’ll have one. You’ll need to prove who you are but there is a Banking. Code covering it (can’t remember the specific one)
Then the ombudsman.

Give them stick on f*c*book or titter, might get attention quicker than a traditional letter and phone call.