I hate shoe shopping too - I'm tall, and my feet are so large it's almost assured I won't ever find anything, especially not if I'm looking for something specific.

Good call on not taking the shoes that would have been uncomfortable - even one day is too much with badly-fitting shoes, you'd be torturing yourself and adding needless stress and pain to a day that should have as little of both as possible. :-) Plus, paying money for shoes that you'll never want to wear again makes no sense!

I'm not sure why your mother and Jean are so eager to have you wear heels, but as other commenters have said, there are some very very pretty flats suitable for bridal wear out there.

In the end, remember that it's really your choice, and what you wear is up to you, not anyone else.