BNP Paribas interview questions

The interview process was good starting with aptitude followed by HR and TL and then department manager.everything was organised and upto the professional standards.i have cleared all the rounds but I was not selected and h I was wondering why they didn't hire my and out of curiosity I have called them and asked..The reason the told was stability is the reason. Because in the previous company I worked for only 3 months. But that's not my fault the company didn't pay me salary than how am I expected to work without salary.this should be addressed properly.