I am having trouble too.
I have, through other card over payments, have a balance with them of $25. They say all I need to do to apply this balance to a diamond purchase is to go to the RoM diamond buying site... select the "Paybycash" option and the amount will be applied.
There is no "Paybycash" option to select.
So... as far as I am concerned... I have been ripped off for $25.
I think RoM needs to be more vigilant and follow up on what we customers are being told by these folks who they have entrusted the money of their customers to.
It'd be nice to have that option for payment we have been told was there to access the money we have already spent.
Selecting the Ultimate Game Card option is technically the PayByCash option. My problem I cannot log in to use my balance. It just constantly loops and tells me to log in. I have to contact PayByCash customer support EVERYTIME to use my balance. Sadly by the time they reply or finalize the order sales are usually over with. For instance this weekend is double diamonds, I have a significant balance but I have to wait on their customer support to do it for me. Chances are i'll miss double diamonds.
As I stated before this seems to be an issue on RoM's end because other games are not having this problems. Each game that uses PayByCash has it's own unique custom page/portal to do so. I just noticed RoM's is so far out of date that it still says Frogster America. This needs to get fixed ASAP as it really is taking money out of peoples hands.