You're risking alot by not fixing things and ignoring the calls.
Sooner or later you'll pay. If you fix things right way, you'll pay a little - and keep your tenants happy. If you fix them later - the situation worsens, your bill grows, and your tenants leave.

They're paying rent to you, live up to your end of the contract!

If you wait for the management company, at least let the tenants know when they can expect the company to visit their unit. Good luck -- mgt companies will charge you for whatever they fix, plus some.