Wealthy Gers fan George Letham and major shareholder Sandy Easdale lent the cash-strapped Ibrox club £1million and £500,000 last season.
Under the terms of the agreement with the SPFL League One champions, they are due to receive that money back as soon as it is in the club account.
But the pair have not received their cash - more than a week after the deadline for season ticket renewals passed.
The Union of Fans want to be granted security over the stadium and training ground, and they have been urging supporters to pledge their money to Ibrox 1972 Ltd.
And it is still uncertain how many people have signed up to watch Ally McCoist's side in the SPFL Championship during the 2014/15 campaign.
This latest development has not helped to make the situation any clearer - and Rangers chief executive Graham Wallace has been encouraged to speak out.
Rangers Supporters' Association general secretary Drew Roberton said: "When we (the UoF) met with (director) Norman Crighton, Sandy Easdale and Graham Wallace the other week they were adamant there was enough money in the bank.
"They also said that they could raise £5m at the 'push of a button' and that all but one of the current investors had agreed to back a scheme should they need additional revenue.
"But I was told on Thursday that around 12,000 had renewed their season tickets. If that is the case, and even allowing for the fact that many will have chosen to repay in instalments, then this might be cause for alarm.
"My understanding was the first £1.5m of season ticket money that came in would be used to repay these loans. It would be good to have some sort of explanation."
Roberton added: "Graham Wallace has said repeatedly that administration will not happen and the club will not run out of money.
"Either he is right and we have sufficient money. Or he has been spouting the party line and he may have to take the fall. He may be faced with a career decision soon.
"Whether his belief that £5m can be raised 'at the push of a button' is included in his forecast is not clear. But season ticket sales are slow and running costs are in the region of £1m a month."
Roberton, who revealed he was "disgusted" at the way the Union of Fans was treated after their meeting with the board, has also urged the club to heal the rift with Dave King.
He said: "The club has said they need to raise £20-£30m to get back to the top. Well, they have a guy, Dave King, who is chapping on their door who is willing to invest £30m.
"It is economically silly to ignore him. The club say they hope to raise money in a share issue. But in far better times Sir David Murray had to underwrite a share issue himself."
A Rangers spokesman said: "The loans will be repaid in accordance with the terms of the agreement in a timely and proper manner. We are in regular contact with Mr Letham and Mr Easdale."
Meanwhile, Rangers chief executive Wallace received hundreds of postcards from supporters outlining why they have not renewed their season tickets when he returned to work today.
The cards were delivered at a protest organised by the Sons of Struth on Saturday.
It was one a series of events the Sons of Struth have lined up during the summer.