I have had a good amount of plumbing issues occur. I've had sinks leak a great deal of water, toilets overflow, back up in the bathtub, you name it. Some incidents were so bad that my apartment management company had to call a plumbing service to take care of it.
The plumber could fix bigger issues than maintenance and they knew more about some of the larger cause than maintenance did.
I'm glad that they did call them to fix it right away. After all, these were all things that could not wait. The plumbers were professional and their repairs lasted a long time.