Phone fell and now Sim won't work

Question

My phone fell and the screen cracked and it still worked fine all evening and the next day. Then when I went to a store to ask how much replacing the screen would cost, the lady (I should add I have an unlocked UK IPhone4S but am currently in Chengdu, China) was clicking around as if she was searching for something and then when I turned it off to give to repair, once I turned it on again the Sim wouldn't work, says not installed. Now once realizing they are trying to rip me off anyway, and now having this problem I compared prices at a few of the (very many fake?) apple stores they all would put another chinese sim that wouldn't work and try to convince me my phone needs much more repair than the screen.
Now going home and deciding what to do/ if it's worth fixing the screen if the whole thing is broken, I put my old UK sim in and it worked! So does my friends UK sim and her Chinese sim. So what on earth did this lady do to my phone settings to enable my Chinese Sim from working???
Anybody have any ideas/thoughts?
Also as there are no authorized apple stores in China apart from Beijing and Shanghai, how risky is it to get my screen replaced by a random store?
Thanks for any help!

Answer 1

I think I had it on the iCloud, I just changed computers and had part of my old computer backed up, where are the default iTunes info saved like the pictures and I know my contacts were backed up cuz I kept getting updated stuff that I wasn't sure about, but it was contacts where some belonged to my wife's contacts....but anyway, if the cloud backed up contacts, it should have grabbed pictures too? Like I asked before, if they were backed up to the computer, is there a default iTunes folder they are saved to? I had a crap load of pictures on there that I usually could really access if I was connected to wi-fi. I turned off my data stuff as I only have 4GB and between me and my 2 kids, we seemed to use up a lot of it. My son would play music from Pandora during work, and use up all our data til I limited him to only 3GB, my daughter and I barely used 1GB. Anyway, thanks to everybody that is answering. I thought I might have done good finding the dang sim card, but pointless I guess.
Ralph - F.Y.I. I would be happy to back up the iPhone if I could turn it on LOL......I am pretty positive I did, but what about Text messages? ANY of those saved too or not? Sorry guys, I don't know a **** of a lot about cell phones, but I do know about memory cards, but not sim cards that act like memory cards or look like them anyway. What is the purpose of a sim card if I may ask a stupid question since they don't hold any data from my phone stuff. I just hope my stuff comes back on the new replacement phone once I get it up and running. Again, thanks to everybody for the edumucation.