In EU? Scoot will just ignore it. And if you try to do in Singapore, they will look at you if you just landed from Mars.
This is the jurisdiction of an EU court. OP does not have to involve any Singapore court.
Albeit, Greek courts are probably very slow, if the OP wins a judgement, that judgement can be enforced (by seizing Scoot assets in Greece).
My recommendation would be to go through a EC261 claim agency.