Sorry for replying to an old topic.
I managed to get it fixed guys, funny thing is some of my friends suggested that it would cost up to 100K , took the vehicle to a AC place in Ratmalana, the technician looked at the issue changed the valve (I think so) did a perfect job. Funny part is it cost only 12K. If you guys need his contact info let me know, I'll drop it here (I don't have it at the moment but when I am passing that side I can get it)
Its working perfectly now its been few months since I fixed it.
Thanks for all your valuable input.