the last line of the Act says it all.
Only secure tenants with 3 or more years to go on their lease or licence are "relevant persons" and so have to be consulted. It doesnt matter how long you have lived there, it is the length of the tenancy still to run that counts
If the joint account was opened when you were married then any debt responsibility is joint and several, meaning the bank can chase you for the debt if they wish.
Now if the account has been used solely by ex-wife then it will be her responsibility as the divorce decree treats financiaol matters as though you have died so a debt she accrues is not yours, even though the account was originally a joint one. Now the problem is the bank wont want to lose a potentail source of recovery fo their money so they wont accept this and it will be damed difficult to extricate yourself from het mess.
IF it is a joint account you are entitled to do a SAR and get all of the statements etc so that way at least you know your starting point if there is going to be a battle.
If thebak refuses to give you the data then they are accepting that it is nowt to do with you
for the debt itself, you cnat be billed for food that wasnt purchased and then supplied, it isnt like a venue hire where they could have made money from someone else if they knew you werent turning up.
The burden of proof will be upon them to prove that a loss has been caused and that wont be possible as no-one shells out £600 on food they know is going in the bin on the hope of suing for it some time later.
Even the venue hire money may be returnable if they managed to rent the place out subsequently. Obviously they are never going to admit this but a cancellation clause is to put them back to square one, not make them a profit for doing nothing
PACE wont want go to court, they have tried that before and got seriously spanked for pursuing debts that werent theirs.
This doesnt mean that they are being clever, they probably havent learnt their lesson but that doesnt mean that you need to respond to this letter though.
Don't touch them owe me £500 since January 2019 make excuse after excuse. Seem they always have software problems sending money out. Keep saying they will call back or email nothing been chasing it now for 6 mths the phone staff always have the same banter we will chase it up and get back to you then nothing!