can i ask for how long hk immigration didnt allow me to enter in hk?

i have a non serious criminal record in hk and i tried how many times to enter in hk as a tourist but immigration hk are not allow me to enter,they always told me "not today".i work as a helper since june 2007 til oct 2010..i exit in hk last jan 2011,ill tried last may 2011 (2 times) and last june but still (not today)i had a lot of friends to visit and i miss hk..