I've only really heard it that way when it's part of someone's name. If it's an actual saint then we'd say it as you expect.
https://www.quora.com/Why-do-British-people-pronounce-St-John-as-Sin-Gin
I've only really heard it that way when it's part of someone's name. If it's an actual saint then we'd say it as you expect.
https://www.quora.com/Why-do-British-people-pronounce-St-John-as-Sin-Gin