Question Author
Thanks for all your replies. The family consists of the mother (been on benefits for over 20 years!) a girl in her 20's also on benefits and they are paid through the post office with a card and the 15 year old boy.I am also sceptical about not being able to open some sort of savings account, but as he has had the cheque since March must assume they are right.
Minty - You cannot cash a CROSSED postal order, it is the same as a cheque
I am reluctant to send that amount of cash through the post and feel I will use postal orders and deduct the cost (£12.50) for doing so. I just want them off my back right now