You should attach two strong electromagnets to the bottom edges of your front bumper to pickup nails b4 they reach your tires.
And BTW, it can be repaired but I also understand the shop declining. On my E90 I had 2 tires that got nails very close to sidewall. I had both repaired with patched from inside. Reason why tire shops don't like patching near sidewall is because of the sidewall flex typically would cause the patch to fail (and because tire OEMs specifically recommend against it). RFTs flex so little the patch can survive as my 2 did. One of them for over 7K miles.
What tires are on your car?