Pay Just Now Refund

I purchased an item through pay just now. The item did not fit therefore I returned it. I then opted for the funds to be refunded back into my account and chose the withdrawal option which was successfull. The company wrote back requesting for my banking details which I provided via email only for the money to be reversed back to them stating that I did not do the process correctly. Now that I am re doing the process, the withdrawal options on the wallet is no longer a visible option.

Why has it been removed? Why was my 1st reversal transaction successful and yet the company claimed that it was not later on? Why request verified for banking details yet they will not be used?