Iphone 5s touch id problems?

I had it for around a week and all of a sudden it stoped working ocasionaly every 10-20 times it works i have reset touch id and done it again and still same

You should have a 1 year warranty with apple on any hardware related issues. I would bring it into them and have them take a look at it. I have heard of many issues with it not working but not those kind of statistics.