I'm going to hang up on this customer because I'm freaked out.
Why is the customer freaking you out?
Because it's a guy who's been talking for a long time.
I understand that you're freaked out, but it's not acceptable to hang up on a customer because of it. The customer needs your assistance, so you should do your best to help him.
No way. I'm not taking the risk of him taking forever or getting mad at me. I don't need to help him, and he can talk to another person.
Someone else could help him, but you were the one that got the phone call, and this is your job. You get paid to talk to customers so it's unfair to your employer and your coworkers, especially if he calls back upset about being hung up on and gets mad at someone else. Try taking a deep breath and asking what kind of help he wants.