I did not qualify for a loan, yet was offered one, had a mandate put on my bank account and had an account for Finchoice added to my credit record

Do not even try to take a loan from Finchoice. They offered and approved me for a loan (got sms's to prove it), Without my permission put a mandate on my bank account for a debit order (apparently part of their pre-authorisation process) and added themselves to my credit bureau report. Then told me I did not qualify for a loan. Have all the emails, sms's telling me the amount is waiting for me. Standard answers from customer care and would not give a managers details for me to contact. They closed the call themselves after telling me I was offered the amount due to a system error and I did not quality. Now I have to get them off my credit report. Why did they put themselves on there if I did not qualify for a loan from them in the first place!!! I am highly annoyed.