The original match was postponed at half-time due to a waterlogged pitch with the visitors leading 1-0 and fans were told over the PA system to retain their ticket stubs.
It was believed that the announcement meant those fans would be admitted free when the game was played again.
However the Tannadice club will charge reduced admission for the match.
Speaking at Rangers' AGM at Ibrox, Bain responded to one angry shareholder who asked why the club had not acted on behalf of the Light Blues fans.
He said: "We did take up the fight because I was disgusted and angry at the attitude of Dundee United.
"The game was called off at half-time and I was standing beside the chief executive of the Scottish Premier League (Neil Doncaster) and the chairman of Dundee United (Stephen Thompson) and I said to them at that time, 'I hope that you will see sense and make sure that our supporters retain their ticket stubs and get back in for nothing'.
"That was obviously ignored. I then had my colleague make strong representation to Dundee United that they should change their mind but it didn't materialise.