Why are all these Naija hotel workers striking and protesting?

First, it was the staff of Radisson Blu Hotel on Ozumba Mbadiwe, Victoria Island. The hotel had to be temporarily shut down after their workers refused to continue work, claiming they haven't been paid for at least two months. In fact they protested in front of the hotel on Monday January 26th. Now it's the staff of Federal Palace Hotel, Lagos. A few of them have sent me emails explaining their own side of what's happening. Apparently, over 100 of them have refused to work, alleging ill treatment and not being paid enough.

Isn't there like a union for hotel workers in Nigeria that can sort this out for members?