Ok, I am in a predicament, I don't want to lose my job or anything, especially as my choices are a little limited but I started working in a bar/restaurant in December 2009 with a 3 month trial period, after this trial period was finished, I was supposed to earn a few hundred more on my monthly wages.

Problem: Still getting the same monthly wages as during my trial period even though my contract clearly states that after the trial period, my wages will increase.

2nd problem with a twist: My boss says that the 13th month wages (which is included in my monthly pay) makes up for the rest.

This is clearly wrong surely? am I being cheated out of my 13th month wage?

Just to specify a little more about the 13th month wage in Gastronomy:

On the 7th month, worker receives 50% 13th monthly wage
On the 13th month, worker receives 75%
On the 25th month, worker receives 100%

I feel it is wrong but if I make an official complaint, I could end up losing my job (pointing out that I have a 3 month termination clause)