Deposit / Buying ZP issues.

Today I decided to purchase some ZP via phone mobile using BOKU ( USA ) but suddenly a strange message showed up to me from the Z8 Page. ( Here's the link to see the image: "https://www.mediafire.com/?u86164vkrkmk08h" ) . Basically I can't buy ZP because my level is too "low" to buy ZP, My rank in CF is Colonel 5th.
Is it a bug ? or is there any problem with the BOKU servers itself? Hopefully I can see answers to this post, I really want to spend some money to buy ZP.

Thanks.

- IGN: NoruNoru.