CARTEGY / CHECK DENIALS

I NEVER EVER HAD A CHECK NOT ACCEPTED BY ANYONE EXCEPT MY CAR DEALERSHIP WHICH USES CERTEGY. I HAVE NEVER BOUNCED A CHECK I HAVE $5, 000 OVERDRAFT EVEN. THEY CALLED CERTEGY FOR APPROVAL FOR $736.00 AND THEY DENIED MY CHECK. THIS ONLY HAPPENS WITH CERTEGY. I HAVE EXCELLENT CREDIT AND OVER $100, 000. IN MY BANK. YOU ARE GIVEN A NUMBER TO CALL "CERTEGY" BUT YOU CANNOT REACH A HUMAN BEING TO SPEAK WITH. SO YOU ARE HELD HOSTAGE BY THEM. I HAPPEN TO HAVE A DIFFERNT ADDRESS (PO BOX) ON MY DRIVERS LICENSE AND MY HOME ADDRESS ON MY CHECKS, DIFFERENT ZIP CODES. MY LAST NAME IS 2 SEPERATE WORDS WHICH OFTEN CONFUSE COMPUTERS. BUT YOU CANNOT REACH A HUMAN BEING TO EXPLAIN THIS TO.