This is 100% why you shouldn't work for a big corporation. You're a resource rather than an employee.
They were trying to nail me into a contract doing even more unpaid work: 'Sometimes that happens in a small company' -> 'Yes, I do the in-house IT, and it's part of the job, but I'm letting you know that it's every day' -> 'Yes, sometimes that happens' -> 'Every day is 'sometimes'?' -> 'Yes, sometimes that happens...'.
The other great comment was 'You have to expect a little overtime when you're on a good salary'. My salary is right on the national average wage - neither good nor bad by definition.
If you're paid hourly, or work as a contractor, you should be paid for all your hours.
I'm in London in the UK, do a 37 hour week, earn $80k equiv, work from home 4 days a week and live about 5 miles from the company (just over an hour scenic river walk or cycle).
Stop selling yourselves into slavery, grow some balls and either get paid for what you do or stop working so much.
Time is finite, don't waste it.