Sales team not informed of company-wide freeze on salary increases - Sales Representative Central Transport Employee Review

my department (SALES) was not informed by upper management of a company wide freeze on salary increases. employees in my department get raises by reaching certain sales numbers, and while this unknown salary freeze was in place, multiple sales people reached their next sales goal but were denied their raise. they wanted us to keep working our tails off (most worked 50+ hours a week) but wouldn't pay us for our accomplishments. i was asked to resign from the company just hours after confronting a VP about a member of our department being denied the raise that she had earned, and telling him it was unfair to withold salary freeze information from a sales group. horrible communication between management and employees. management doesn't want employees to have an opinion or stick up for one another. company is horrified of the word "union"