Whatsapp in my phone

Hello,

I have a kgtel GX5 phone with me... No idea of its OS.. in sefifictations it says as propreitary...Jawa symbol is there but when i open i can see games only... No app store but fb, watsapp icons are there on the phone... when i add number and try to verify whatsapp, a TM code is coming to my phone and after five minutes it says could not verify... no option for typing in the code or calling for code or resned sms... can you help to find out how to enable jawa in this phone. or what its os is or what to do with this.pls plspls