With only 8 owners, can you and another EC member simply walk around to each owner and explain the difficulty of getting a response from the managing agent and directly ask if they have paid their levies.
I am treasurer of an OC with 105 townhouses. I can log onto the managing agent’s system at any time (with a password) and see all account payments and the state of levy payments, where the budget is at and our overall account balances. We are paying a bit more than you per month for the strata manager but we are 105, not 8.
I think you should be jumping up and down rather more to know who is in arrears or where the money went if no-one is in arrears. If unit owners in arrears are preventing maintenance work from proceeding you need to get heavy with them. Start out nice at first but don’t dally too long at that stage.