Can the lounge please check my logic?

[discntnt_irny_srcsm]

4. The problem is with how they've phrased the policy

"Up to 50% of your Vacation hours may currently be carried over into the next calendar year, they must be consumed by March 31st of the following calendar year."

This statement may be grammatically interpreted to agree with your statement. However, I feel that it is somewhat obvious that the intent was as follows:
"Up to 50% of your Vacation hours may be carried over into the next calendar year; they remain available until March 31st of that year."

You would have trouble convincing a party of your position based on the phrases "into the next calendar year" and "of the following calendar year" apparently not agreeing. Your assertion (that 14 hours of 2015 vacation) remains available until 31 March 2017 falters a bit in that the New Year's 50% reduction could be applied twice to the same set of hours.

Arguing with payroll may not be in your best interests.