Lost money

Wonderboys

My son paid off a castle community bankloan of 12500.00 on their site as discussed with them on the phone. A month later he received a statement with no 12500.00 deduction. Following that up we rang them and they said they didn't receive it. They looked into it and thought it had been paid to community finance who are brokers to castle bank.  We contacted Barclays who paid the loan via debit card and they now want more details. He has none.
Where is this money and what can we do? Any advice gratefully received

marcia_

 Did he use the correct reference when paying? Its easy to make a mistake. I paid off my next account and put the wrong reference in and my bill arrived without the payment on. On telephoning next they asked for my card number and traced the payment to a holding account used for daft people who do the same thing every day.