Working in a call centre for mobile phone insurance. It wasn't sales, it was receiving incoming calls. Basically the company took £5 a month from people to insure their phones but either didn't pay out or gave people refurbished phones as replacements. So 8 hours a day of mostly fielding calls from irate people asking to talk to managers who didn't exist or didn't take calls if they did. It was also company policy that you couldn't hang up on people so the job was basically getting rid of people as fast as possible. No doubt many people rang back many times over the same issue.
Really soul destroying.
Really soul destroying.