I called about a bill I recieved two days in a row...

I called about a bill I recieved two days in a row at 6:30 pm, on their letter it says that they are open 'till 7:30, their answering machine says they are open 'till 8. Even though I called at 6:30, the answering machine picked up saying I had called past buisiness hours. So I waited for a call back the day after, and they never called back. One more day goes by and they call me back, it was a machine and not a real person, so I called and got to talk to a real person, who HUNG UP on me! Not impressed with the level of unprofessionalism.