It might just have been worth mentioning to the team leader, the office manager, or HR, whichever seemed more appropriate in your workplace, that this person's well-meant gesture might easily pressurise a whole office into gift-giving that had been getting on just fine without it, and could they see what they could do to stop that happening? It's very easy for one such action to start a domino effect, so that everyone ends up feeling obligated to spend significant money and thought on presents for their colleagues, and that's something that management should prevent.
One way to stop that happening is to have an official but strictly low-key, low-cost gift exchange. I think I may have told how my own old workplace used to do it on the ehell board, but it was the best system I've ever heard of, so here goes again:
A few weeks before Christmas, Santa's sack would appear next to our team leader's desk. Everyone would buy a stocking-filler-type item suitable to any gender below a given value (originally it was £5, but over the years it went up a bit), wrap it nicely, and find a moment to surreptitiously drop it in. At our team Christmas lunch, someone would be designated to be Santa, and they would dip at random into the sack saying 'This is for Ashley! And here's one for Deena! This one's a weird shape, let's say it's for Tareq!' till everybody had a present. (You were allowed to say, 'whoops, I put that one in - drop it back and give me something else'.) it was great because there was minimal cost and no angsting about 'what on earth would Shirley like?', but lots of festive unwrapping and jokes about who got what. And if two people actually preferred what each other had got in the lucky dip, there was no possible offence in their openly swapping them.