How is having a discussion with management about PAY not appropriate? It’s a job. Pay is a pretty common topic.
It really was a bizarre situation. As though none of the managers could handle confrontation or simply answering a question. They should have outright told you to find other work instead of this insidious “ghosting” tactic of 1. no longer giving you new clients, 2. not paying you for every task, 3. telling you to apologize to management over asking about something perfectly normal, something they would ask about if in the same situation, 4. taking away clients, 5. and finally trying to gaslight your work and reputation. What a huge waste of time and resources.