Have had it happen several times. VERY annoying - especially since I only deal in peanuts these days as opposed to buying expensive watches on a regular basis before.
Follow their asked for procedure in regards to the information they want.
Then wait for a few days (in this case you might have to wait till the new year though) and then contact them.
Tell them, that you have supplied the info they wanted and that you would now like the account re-opened, as you have transactions pending. Be cool, calm and collected.
If they do NOT open the account, then it is time to play hardball and call them and demand to talk to someone in charge.
I have supplied the info they wanted and then called them. Last time, that they closed my account, I called them right away and yelled at them, as we had just been through the circus recently. They re-opened the account within minutes.
Usually, it is just a routine anti-money laundering procedure which unfortunately is an inconvenience for innocent people. Again, I am amazed, that they froze my account, as I only have transactions for minor amounts these days. But most likely just routine.
It might be a good idead to think about how you use the "gift" feature in the future, as they might be cross with just that feature (just a wild guess on my part of course).
Most often it is, as mentioned, just routine freezing of accounts.