First step is to ask to see the contract by which the Strata Manager is acting. If they wont answer emails etc the best idea is probably to call up, then to go the office and ask for a copy of the contract. Go over the Manager’s head to his/her manager if needed. Ask if they are a member of the professional association of Strata Managers (maybe they disclose this on their website?). Threaten to invoke the professional association if they are not co-operative.
I presume you are an owner? (You say “reside”.) Keep in mind that as an owner you are “the boss” of the Strata Manager – these people work for you!
If there is no contract in place you should be able to sign up another Manager – once agreement is reached between all owners. Talk to your neighbours now and let them know the lie of the land – that they can choose, they can take part in decisions. Bear in mind many people don’t want to take part or make decisions!
If there is a contract in place, find out the term of it and it may be a case of waiting until it expires. But have your ducks in a row well before then.
When comparing costs of contracts, be aware of different models – some Management contracts look cheap until they start to charge per page and per lot to send documents. Often better to go for a more expensive all-inclusive contract.
Good luck.