What do you want to get out of breaching the strata manager.
You can ask the committee to speak to the strata manager to improve their performance.
The strata manager can only be removed by a court and you have to prove they breached your contract .Easier said than done.
A motion to mutually terminate the contract is not necessary. The strata manager and the committee can agree to this.
If you are so unhappy it’s better to cut the ties and put this down to experience. Remember that the outgoing strata manager has obligations under the act to do an orderly handover.
Divorced and contract terminations never go well. Usually the only winners are the lawyers. Remember try to be happy and not necessarily right. It’s the cheapest and quickest way.