I worked at 3 different call center jobs.
First was outbound sales. It was by far the worst job I have ever had. 8 hours of making non-stop phone calls to people who didn't want to talk to you, reciting the same script over and over. My throat hurt every day when I went home from talk. My brain hurt, I couldn't relax EVER outside of work. I was already thinking about how I had to come back in the next day before I even got off of work. Lasted a week and had to walk out on the spot. Getting cussed at and all that didn't bother me at all, I actually preferred when people got pissed and hung up on me because then I didn't have to recite that script.
Second was inbound calls, doing directory assistance looking up phone numbers and addresses. It wasn't quite as bad, I lasted 3 months this time. It was still stupid as hell...I basically got punished for even taking bathroom breaks because they monitored every minute that your computer was logged out. It was a non stop shyt show the entire shift and was boring, repetitive, and draining.
Third was an actual professional job as a trucking company fleet dispatcher. This probably wouldn't be considered a "call center" job by most people, but it was the same environment because my shift was a constant stream of inbound and outbound phone calls often with multiple people waiting on hold. This job nearly destroyed my marriage and my personal life. It put so much stress on me that I lost 20 pounds the first month I was there because I couldn't eat. The reasons it was so stressful wasn't necessarily just because of the constant phone calls though, there was a lot of other shyt. I quit after 4 months despite being an adult and actually having real bills and responsibilities this time. I put myself into unemployment.
Basically, call centers are the worst jobs in the world. I would literally rather scoop piles of shyt from one spot to another spot then ever work in a call center again. The only people who seem to be able to work in them successfully are drug addicts and drunks because many of them don't drug test and it just feeds their partying lifestyle.