Robert Kiyosaki Rich dad Poor Dad Paid deposit for seminar. Company says deposit not valid for seminar. Internet

My husband and I attended a Rich Dad Poor Dad free seminar Sept 2009.  We paid a $49.00 deposit to attend a 3 day seminar but stated we could not attend the next one as we would be overseas.  We were told this was no problem, we could schedule the next one.  When we tried to reach Rich Dad, we were told the $49.00 was an inadequate deposit (although we gave proof that they dud charge our debit card).  We have sent multiple letters since and called, to no avail.  No response, even to certified letters.