Not sure what the issue is.

[Immortanjoe]

I recently had a plumber come by and replace the internals of the tank on my toilet. it's constantly running now, so I went in and noticed the water right at the top of the drain tube. I couldnt tell if it was overflowing, so I adjusted the float to it's lowest setting. It still continued to run. So I did a diy adjustment to the overflow, just to see if I could stop it running, but I noticed the pipe running into the drain tube (I'm sorry, I don't know the technical term for it.) was constantly on, which might be the cause of the problem. I attempted to lift the float to see if it stopped the flow, but it didn't stop.

I'm not the best at explanations, but I wouldn't mind some feedback. Is this a simple problem, or do I have to call my plumber back?

 

[Jeff Handy]

Call the plumber back.
The fill valve could be defective, or have minerals stuck inside which make it keep running.
He might not have flushed out the supply line and shutoff valve when he installed the new one.
You can close the shutoff for now, to turn off that toilet.

 

[Geofd]

Jeffhandy correct sounds like a defective valve call him back