I recently got a Samsung Galaxy S2 GT-I9100 from my girlfriend which was locked to T-Mobile (it had been a contract phone). My contract is on Orange so I flashed an insecure kernel in Odin and used Samsung Quick Root to root the phone. I booted it up and managed to unlock (though i'm now not sure if this was a full unlock or some kind of soft-unlock, I don't know if that's even a thing - I used an app called "Galaxy S Unlock"). Anyway I tried sending a text just to make sure and it was fine. I decided to install CyanogenMod (latest version on the website), I did and all was fine. Then I was prompted to update on my phone so I did, halfway through it crashed and - being an idiot - I turned off the phone. After that I could only get as far as the Samsung logo when trying to boot and after that it would return to a black screen.
I did some Googling and decided to flash back to a stock ROM which worked and the phone booted fine. Now however, the phone asks me for the SIM unlock code (making me think this was a soft-unlock) yet I still get bars of signal but if I try to text or call I get the "Not Registered on Network" error. I've tried adding Orange's APN manually but it won't save, everytime I press save and go back into the APN it's blank. I've also tried to select the network using the "Select automatically" as well as trying both Orange and T-Mobile in the network options and simply get an "Unable to connect. Try Later" error. I've also tried to update through the phone and it says it's upto date. I'm currently running Android 4.1.2. The Baseand Version is I9100BVLS4 and the Kernel Version is 3.0.31-889555 with Build Number JZO54K.I9100XWLSY.
Could anyone give me any advice as to what to do? Thanks!