Transfer From Another Credit Card

To put my feelings into the vernacular, this bank SUCKS.  I have now notified my representative (who is ourSpeaker of the House) the attorney general of the state of OH, and am working on various banking associations.  What CITI is doing is simply illegal.  This came to my attention about 6 months ago when CITI bgan a relentless calling campaign to me.  The deal was that Icould transfer any amount of money from another credit card or simply call it an INTEREST FREE LOAN for 13months.  I pay in full each month and have an excellent credit rating and history but I am not stupid either.  13 months of using money free was not a bad deal and up front costs were minimal-maybe $300 for a $10K transfer.  Again--no interest.  however, when I received my next month's statement (which I pay in full to avoid any interest,)I see a $50 interest charge.  I called (Bangladesh or India) and said--"WHOA- I paid for all of my charges in full, on time, and added $1000 in order to begin the elimination of the free $10K."  I was told the interest charge was an error.  next month, same thing. and then the third time,  I went thru channels and got a CITI BANKER who explained CITI takes your payments and applies it to the outstanding (interest free) amount FIRST, and then with the remainder charges interest, so this 3rd time, my interest was $3. since then I have stopped using my CITICARD totally..The point is:  THEY CHARGE INTEREST TWICE:  FIRST ON THE AMOUNT THEY SO ENCOURAGE YOU TO TRANSFER, then THEY CHARGED A SERVICE FEE FOR DOING SO, and THEN THEY CHARGE INTEREST AGAIN ON THE UNPAID PRINCIPAL WHICH would mean a monthly payment EVEN IF you don't charge anything.  AND TO THINK I DID THIS TO GET 10,000 MILES ON AMERICAN.  ok, I am stupid.  But this is illegal