OP - why not just go across the road to another supermarket or try the wet market? I doubt they ran out and are probably cheaper to start with.
They are still having 30% off for the pork.
Any suggestion for frozen meat shop in Tsuen Wan - I managed to find the following list of available options:
You can also order online from places like tenderloin.com.hk
They have great quality and selection. They have fresh and frozen. Ends up being far cheaper than anything bought at supermarkets, and yet quality is far superior.