From The Faq:
Golden members have much more demand in renting referrals compared to standard members because almost all of them can afford to rent.
As the demand rises, the distributed referrals for a particular time are easily sold out.
Golden members can rent referrals by setting two times of the day for renting depending on their most convenient time.
You can find that option in your personal settings.
After you change the time, you can only change it again after 7 days.
Remember to be quick because many other members will be there at the same time as you trying to rent.
If you're having trouble renting, you can always use the rental queue which, while being a bit more expensive, will guarantee you the referrals.
Also check out these great posts they will help you a lot:
[Tips] Renting Refs Golden (Click Here)
Special days of week for renting. (Click Here)
Golden Renting Instructions