How can I hold the property manager more accountable?

Broken down in its simplest form – it comes down to your contract with your property manager.  You lease itself should be between you as owner and landlord and the tenant as tenants.  However, of course, you hired the property management company so you wouldn’t need to deal with the day to day problems (at least that’s my assumption).  So, to answer your question directly – what’s your recourse against the property management company?  Sounds like it may be a breach of contract.  Of course, your likelihood of success comes down largely to what your contract with the company says.  If you just want to be rid of them (rather than suing them), you would essentially be arguing the same thing – that is – that the company breached the contract.  Again, to be clear, this comes down to your contract with the property management company.  I’d say to sit down with a lawyer to discuss the contract and all of the facts and see what your options are… then create your game plan.