Completely Off and sour smelling sirloin meat

Meat World (Meadowdale Mall)

I purchase alot of sirloin steak / porter house Approx 3-4kg (which is quite expensive as it is) it's already been 3 times that I have experienced off and sour smell from the meat when I package it my self straight from purchasing. It brings me to the inconvenience where I am having to go back to the store and bring this to there attention (as usual they try to be defensive and ask silly questions like has the meat been in the sun etc to try cover themselves) which in my response it's a straight no. They then refund me my money back and basically that's where it stands. Perhaps they should refund my gas money spent too for having to travel abit of a distance to return the off stock they supp**** me in the first place.