Cant help you other than to say 'take it back'. I once got a Bianchi OWB from Green Top that someone had apparently purchased, modified, and returned. The adjustable thumb snap would not fit over the hammer because at least 1" had been cut off the velcro side of the top strap! It would be nice if they checked stuff out before they put it back on the shelf :X
For future reference Southern Gun World in front of Dominion shooting range has an excellent stock of holsters. Including Serpas.