Dear cathy webb,
There could be many reasons for this. Maybe the battery is damaged/old, maybe it has another type of technical problem. Thats why i would suggest to you the same thing that i would do; send it to a repair shop. It usually costs between 7-15 US dollars to get it fixed, and it can usually be done for a couple of hours.
As i see you have received this watch as a gift. Have you received the whole box including warranty card and the purchase receipt? In case you have received those, you could try and retrieve the watch to an official CK dealer, and maybe they will give you a new one or repair it for free. CK watch warranties are for one year and your watch is still covered by it (assuming it was purchased less than 1 year ago).
I am not aware from what country you are, but some of the official CK Watch stores can be contacted here:
Hope i could help,