Double Debit, No refund

I had a loan with [URL Removed] and changed my bank account. I was told that I cannot change my banking details with them while I have funds outstanding. I then requested their banking details so that I can make a manual payment on 25/08/2015. To my suprise once funds were available in my other account on the morning of 29/08/2015, they immediately debited despite assuring me that their money was indeed collected when I made the manual payment. <br> <br> Because this is my rent money, I need it back with immediately so I spoke to a less than enthusiastic lady on the phone on Monday, 31/08/2015 at 7a.m who assured me that the funds will be available within 24-48 hours. I called again yesterday at 7a.m and the same lady assured me that my payment was in fact made. <br> <br> The funds are still not available in my account and because this is part of my rent I face eviction. I tried to apply again on their site but it no longer approves my application.<br> <br> Can anyone offer me advice on legal steps I can take against the company because if I have an outstanding amount it accrues interest. The only interest I will get is on late bills.