Guys they are selective about newbies. Once you are established for awhile and they see how your sites develop they will accept you or they may even invite you.
I think the rationale is they want to maintain a professional affiliate team and not get burned by brand new affiliates who will promote them via cheap spam lists, garbage pop ups and on poorly designed banner farms that produce no real players anyway.
Over exposure through poor channels does no one any good, so I respect their decision to be selective when approving new affiliates. Just hang in there and try them again in three months.