Ive worked in call center as tech support all my adult life so i can very quickly answer this (and im sure they advised this in training if they trained about customer service at all) but it helps a super ton to always remember that they are irrate at the company, not at you. You are just the person they got when they called. All companies have different policies on customer abuse to a rep but at my company if the cusyomer calls me something like a c*nt or something i know will make me fly i to a rage i will state "Sir/M'am, I understand that you are upset but please keep this professional". Going further into customer service training, helps a super ton to ALWAYS smile as you talk. It changes the tone of your voice and the person can "hear the smile" and a lot of times a screaming customer calms down with a "smiled voice". Put a mirror on your desk if you need to. Let them vent without interuption. Generally when they have gotten it off of their chest, they relax. If they are yellong over needing a spelling of a name my favorite is "Oh I appologize Sir/Ma'am, Im just horrible with names". I mute a lot (making sure mute works on my headset/phone first) and yell back, they cant hear and it makes me feel better. Turn down the volume, its easier on your nerves if they arent blowing out your ear drums. Leave yourself notes on the monitor. My favorite is "deep slow breaths, you are floating on your back on water" and i close my eyes and imagine that as it takes me from 100 to 0 pretty fast. And i didnt read if you are on any meds for anxiety? If not, it may be a needed convo with your PDoc. And empathy empathy empathy.
Its hard working at a call center being screamed at all day beung called every name one can ever dream up. Go easy on yourself. Also, if its a long term job, and if they havent trained you on or dont have customer service training it would be worth searching on youtube for "customer service training" or "customer service tips" or "how to handle irrate customers in a call center" or really anything, there are many many videos, sites, etc for free you can get a lot of good tips and what not in handling this. Hope this helps some.