Well insurance they would hit you....
Your friendly parts department may be able to
help or one of the boards sponsors. The glass clips in so it depends whether anything else got broke, you'd pull out any lugs and clip before fitting if anything still present.
Had a similar situation when I first got the
Ateca. They hadnt clipped in all the way the heated wing mirror plug that goes inside for the heated wing mirror at build. The dealer broke the glass saying in the cold weather there is a 50:50 chance it will break when you try to unclip it. So he used a donor
Ateca in the dealer to give me a mirror but didn't have the blind spot window in it. Said I'll order one, you can either pop out this and I'll send you one to fit yourself or we'll do it. I let them do it. He took it out, broke it, out a donor one in, then two weeks later unclipped the donor one and put the correct one in after ordering it.
For you the work has been done if no other damage, you just need the correct mirror to clip in. As said you might find a piece still in a clip. It's these on other Seats they whip out the mirror to then unclip the surround to put different coloured wing mirrors cases on. So people here know about getting them out. You press in places and then it comes out. Perhaps your local vandals collect different cars mirrors

. May be had an eye on the shell but decided it wouldn't fit or just fell out....
Here are the pages from Erwin on the
Ateca mirror replacement and fitting plus info for those that want different shells.
Formentor will be similar.
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