Can you not think of an example yourself?
Ok. Someone I know works in a call centre. The shift pattern calls for 10 hour shifts, which can be from 8-4, 12-8, 3-11, three days on, one day off, two days on, two days off. Her working hours, and days off, change from week to week. She has no say on her scheduled days off, start times, end times, or breaks. Her company offers zero flexibility on any of this. Holidays are booked through a company wide (national) system, twelve weeks in advance. She is very often unable to book the holidays she needs and has lost holidays as a result, since her contract does not allow holidays to accrue or be paid in lieu. She is not entitled to bank holidays either, and does not get paid overtime for working them. Additional hours are available, which she works, but they do not attract a premium.
Her job involves taking complains from members of the public, and she is supposed to cross-sell and up-sell while she does so. As the voice of the company, she has people channel their anger and rage at her all day, every day. Which is stressful. She also frequently has to deal with difficult situations such as taking calls from bereaved customers, people in financial crisis, customers who clearly require additional assistance and so on. She also has very little control over how she is able to resolve their complaints. Escalating to a manager is possible, in theory, but many managers simply ignore requests for help. If she transfers too many calls, or escalates them elsewhere, she will be disciplined for missing her targets for call resolution.
She is monitored by software every minute she is at work and has to log her toilet breaks. If her adherence dips below 95% she will receive a verbal warning, and, if again, disciplined. Her performance on the phone is also continually monitored and spot-checked. There are no 'off' moments on the job.
She is paid £6.15 per hour.