Do not buy diamonds from the us Runes of Magic. They do not inform you at the point-of-sale that you can not use these in-game at the Auction House for 30 days.
When you complain about it & inquire about a refund via the support system, mentioning that this is something that the Better Business Bureau should be informed about, they ban your account & still do not refund your money.
If any of you have experienced this too, please file a complaint at the BBB of california, as the business information is :
Frogster America, Inc.
548 Market St #22350
San Francisco
California 94104