Thanks for the responses everyone, I got the GearBox replaced. Actually first I got a quote from Nilwala to repair the gearbox for 50K, then again I got a recommendation from a friend to go to "JENNET AUTOMOBILE REPAIR CENTER - Athurugirya" who had a look and promised to get it done for the same price, and I choice "JENNET" as they were recommended by a trusted friend.
Unfortunately, JENNET AUTOMOBILE REPAIR CENTER did a very bad job, as a result, I had to consult Nilwala who advised me the GearBox is no longer repairable and I had to replace costing me 150K.
If this helps anyone with similar CVT gearbox situations go with Nilwala.
Thanks!