I'm a 20 year employee and have 6 weeks vacation. I received a letter from work stating I now only have 4 and that they will adjust my salary up by the equivalent of 2 weeks pay. Can I refuse or do I have to sign?

This unilateral change by your employer may amount to constructive dismissal of your employment. Before you sign anything, you should reach out to our office for a consultation to understand your rights and entitlements in these circumstances.