I don't know what the merger fund is about, $120 sounds pretty steep. Given the total lack of regional mergers taking place that seems unnecessary to me.

However, you have to take some blame for the dues situation. After being in the industry for a year you had to know that dues would be taken out of your paycheck after your probation ended. When you got that first paycheck with the higher rate of pay and no union dues deduction, you should have been following up with payroll. You'd do the same if they shorted you pay, and it would have been easier to just get it fixed rather than get a bill in the mail.

That being said, we have guys delinquent on dues at my airline for thousands of dollars. While it's technically possible for the union to force the company to terminate you for non-payment, I don't see it happening except in totally rare cases.