Think twice before buying parts through Mitsubishi Zambezi

I took my Mitsubishi Pajero to Mitsubishi Zambezi for a checkup and as my rear screen wiper arm was broken and I needed it fixed for purposes of putting my vehicle through the test the next week prior to going on holiday, I requested if one was available in stock. I was shown that indeed 3 were available on the system and that it usually takes 48 hours for delivery, i.e. Thursday. I immediately paid the full purchase price for the part to ovoid a situation where it is out of stock. I was informed that the part was ordered immediately while still available. I need to stress that the part was needed latest on the Friday otherwise I would not have ordered it. Needles to say, it did not arrive on Thursday. I requested that I be informed when it arrives. I made enquiries once again on Friday and was informed that the part was on back order and that it would take 4 to 6 weeks for delivery. not acceptable as they knew the circumstances under which the part was ordered. In any event, back order where the part was available just does not make sense. I requested if they can attempt to source the part by Monday and inform me if they could obtain it. I received no communication whatsoever. On Monday I called again and only then was I informed that no part could be sourced. Obviously, I requested my money back as I had to attempt sourcing a part myself. This is where it got trick. I was requested to provide my ID (this is acceptable for purposes of a refund); a bank confirmation letter (not on) ; and was to sign an indemnity (fine). I just do not understand why all this is necessary even though I informed them that I would personally attend their premises. I just do not have time for all this. They allowed no scope for the terms of re-payment. They did not honour their agreement to provide the part. They did not call back or at all. They make it extremely difficult to get your money back. The customer does not come first but money does and that is unfortunate. I hope this is not a reflection of how Mitsubishi does business in general, except that I was told by the branch that placing the part on back order even though paid for and booked and the repayment terms are standard practice that should be followed.