I used to do all my shopping at Sobey's in Toronto, but have switched to a Metro nearby.

Here is some free advice to win back customers:
1.  The staff seem surely and disengaged and not just at one store but many.  That tells me something is wrong with the organizational culture  because the fish rots from the head down.
2. Your prices are far too high, full stop.  
3.  Please stop the practice of Buy 3 and save or Buy 4 and save.  This marketing gimmick is just that and once I see that I just keep on walking by.
4.  What really drives me crazy, and was the tipping point why I stopped shopping at Sobey's, is when they mark an item on sale rather than just the sale price they put the old price and a fine print that says, "you may save"  $2.53.  So one never really knows what the sale price is rather you may save this amount which tells me I won't save that amount.  Again you are trying to deceive the customer.

Good luck with the restructurin but the change has to come from the top.