Nissan Primera P10 (1995 Model) - Air Conditioning - Famikuns

Hello

Please can anyone educate me on what to do to my car, I filled the gas recently and just about two months after, it does not cooling again. I realised that no more gas in it, I took it to where i can work on it, after thorougly checked no leakage was discovered. Pls, What do i do to rectify this problem?