Touchscreem won't work.

[Android Question]

Hi, I have a Samsung Galaxy Ace Style. It's pretty new (around 3 months old). I tried to turn it on this morning but the touchscreen won't work. All the other buttons do, but I can't unlock it because I can't 'swipe to unlock'. It also says that my SIM is not inserted. I tried taking the battery and SIM out a couple of times, it loads up fine, tells me I have messages (so the SIM must be working at some point) the touchscreen still won't let em unlock it, then after a couple of minutes it says the SIM isn't inserted - emergency calls only.

Any ideas what the problem could be/how to fix it?

Thank you for any replies.