Need new strata manager – advice please

Our strata manager is no longer providing a service we expect. I would like some advice on the best way to ask the strata company for a new manager. My aim is to do it simply and painlessly without burning bridges. Hahaha

We are in NSW and all owners are supportive to ask for a different manager. The current manager doesn’t acknowledge emails and I’ve waited over 7 weeks for a reply. Never available to answer the phone. I only got a terse 1 line reply to say I was out of line when I took it upon myself to organise strata maintenance. Other owners have similar stories. There is no advice or guidance and often the information provided is wrong. It is a real struggle and a waste of my time constantly trying to demonstrate diplomatically that the information is incorrect. The list and stories go on. 

Any advice would be greatly appreciated as I really don’t want to create extra stress for anyone. Thank you this forum is invaluable.