I’ll answer, but before I do, you did ask
If it were me and I thought it might be a mistake by them, I’d check with them to make sure they didn’t give me the lens by mistake. I know it’s easy to take advantage of an issue, but I wouldn’t be able to do that (in fact, something very similar happened to me a couple of weeks ago and I returned the item)
Not trying to moralise at you or come off high and mighty, but you did ask ;-)