Still waiting for my money

I have a loan with the bank, I have a debit order arranged for the last day of every month but for some reason in December they debited before my pay day, as a result that left me with charges from my bank because of the failed debit order. I reported this at the bank on the 28 of December and requested to be reimbursed, I was told to allow up to 14 days for the matter to be resolved. The date is now the 22 of December and I have not had anything from the bank. I am not happy about this.