[hnbad]

In Germany you can also get documents notarized in (Catholic) parish offices. I think they do it for free.

That said, this sounds unreasonable and if you're not in the US this may violate consumer protection regulations if they didn't require the same level of verification to sign the contract in the first place.

[chpmrc]

It is unreasonable but it's just not worth engaging with them even to exchange a few emails, financially speaking :)