Credit card refusal letter, is it mandatory?

I applied for the BOI Visa. After 6 weeks having heard nothing I emailled Card Services and after an address confirmation the rep said my app was refused. He also said a letter saying that was sent
(I remember a prime time documentary about AIB where they wrote letters and filed them, but never actually posted them). I said I never received the refusal letter, and asked for a copy. But they have said and done nothing since.

I want a refusal letter on file because the app form included a signed direct debit mandate which they could use at some future date by mistake, or even worse I could get a letter saying I owe BOI 10,000 for using my card, and I'll need proof that I never had a card.

1. Does a potential credit provider have to provide a refused credit seeker with written confirmation of refusal?
2. I an email good enough or must it be a letter?

Write to the bank's credit card unit directly by registered letter (do not sent it to a PO BOX number)

Head the letter official complaint.

State that you have a copy of the letter and it has been sent by recorded delivery.

Ask for a refusal letter and give them a time frame in which to respond e.g. 5 working days.

Also, suggest that if they do not respond you'll have to discuss the matter further with a Data Protection Commission representative and the Financial Services Regulator.

why did you get refused a credit card?

As far as I know, If you register as a student with any third level institution by paying the fee for the initial student ID (but drop out later and dont pay the fees) and bring it to BOI as proof of student status , they would give you a a student credit card with no proof of income.