Ship back immediately. Any loss of money is a cheap life lesson.
When I was young (24) in the early 90's, I got a call at work in regards to purchasing stock. I had a little extra cash at the time and was coincidentally thinking about getting into some stocks. The broker had a good story, and I think he was working off of a company phone list that he acquired. I signed up and purchased two stocks over the first year for about $4,500. The stocks tanked and this was in retrospect a shady stock selling scheme. The broker got big commissions for selling garbage penny-stocks to suckers (me). I think I ended up losing about $2500 total. I even received a notice from a government agency that was investigating the firm years later.
The $2500 lesson taught me to learn about investing,
never trust a financial advisor, know who you are getting into business with, do your own research and understand what you are buying, and to take control over your financial decisions. It is OK to make mistakes, as long as you learn from them. The watch you bought could have just as easily been a house or major investment in the future. Better to learn now when you are young and have no money.