Amazon Excuse for withholding seller payment Internet

I sold several items through Amazon, and when I requested funds be disbursed to my account I received a "credit card not valid" message (they have to have a valid card on file in case they need to charge a refund or something).
Anyway, the credit card was valid- and in fact, I had used it recently to purchase on their site. Not only that, but when I went to enter the "valid" information again so that I could receive my money, I received an error message that the site wasn't working and try again later.
So I emailed them, and received a reply stating that I had fixed the credit card information, but I couldn't request "another" disbursement since it had been 24 hours since the last request (never mind that they didn't make the disbursement!)
So beware if you sell with them, actually receiving the money is another matter (also never mind that they charge a large commission, and the shipping allowance doesn't come close to the actual cost for most books).
I think I will go back to the old fashioned method of a postcard on the dormitory wall!