The place to diagnose SIM card errors is with the SIM card supplier...sadly, that sounds to be quite some distance from where you are now.
What you could do is try a SIM card from a local carrier...assuming your BB is properly unlocked, of course...to try and see if it's the SIM card or the card reader on the device.
Otherwise, you will need to contact your SIM card supplier for formal support.
Occam's Razor nearly always applies when troubleshooting technology issues!
If anyone has been helpful to you, please show your appreciation by clicking the button inside of their post. Please click here and read, along with the threads to which it links, for helpful information to guide you as you proceed. I always recommend that you treat your BlackBerry like any other computing device, including using a regular backup schedule...click here for an article with instructions.