All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.
If you have a special agreement that you are entitled to a vacation allowance, then even five years have elapsed, it is still your right and they must pay you for your vacation allowance.
However, if there is no prior agreement about it (between you and them) and the labor law stipulates that you are not entitled to the allowance after that period, then you have no right on them.
Allah knows best.