So my question is:
Can I reinstall BB software and get my original PIN & IMEI ? I never heard there's a way to altered IMEI or changing PIN ? Can I restored the PIN & IMEI to original and use BES again ?
Unlocking has NOTHING to do with the PIN/IMEI. I am guessing that the user either used a tool they didnt know how to use, OR the device was reported lost/stolen and the PIN was blocked.