There was no encroachment done by them because you got your land surveyed and got the boundary stones fixed accordingly protecting your boundaries of your landed property.
Therefore there is no cause of action at all if you got them solved by yourself.
You can take action through police and court if they one again occupy your property.
As far as the allotment of government poromboke land to them to extend their crematorium, it is the policy of the government, if you and the residents of the surroundings are affected by this extension, you can file a PIL before high court and get the allotment stayed.