Don't doubt your GPS. Heritage Fish & Chips really is in the plaza where you'll enter but it is all the way at the back. There, you will find a quaint little pub-like interior filled with all sorts of British knick-knacks inside.
I originally sought out Heritage Fish & Chips after finding out that Mississauga Fish & Chips was closed on Sundays. While there is only so much one can do with fish & chips, it is possible to screw it up so I don't like to chance places I don't know. Everything worked out at Heritage so I've now got a new option in the area!
Prices are better than fair and portions are enormous. What's not to love?