"I asked if they were members," said Bates in the Yorkshire Evening Post,
"Once the answer was no, the answer was simple. You're not getting a ticket."
Leeds are confident that every season ticket holder and club member has obtained a ticket for the club's biggest game since the 1975 European Cup Final.
United placed strict restrictions on their ticket sales, members of staff were unable to purchase any more than two tickets each and Bates is satisfied that the allocation has been split fairly.
He added: "The sales have been done in such a manner that nobody has been able to pull a fast one. We have turned down plenty of requests from outside parties.
"Once we discussed the final tickets everyone was unanimous that it was the genuine fans that should get the tickets.
"They have responded in their droves and I hope they will be rewarded on Sunday."
Around 95% of the corporate hospitality sales at the Millennium Stadium are also understood to have gone to Leeds supporters and in excess of 40,000 Whites could be in Cardiff on Sunday.
It will be the biggest following for a game outside Leeds in the club's history.
In contrast, Watford have sold little more than 25,000 for the Millennium Stadium and tickets are expected to remain on general sale at Vicarage Road until 7pm tonight.