Comment by JesseWright

I definitely second ACR. I use it and have it set up to record literally every phone call I make or receive. (You might need to be mindful of espionage laws depending on where you live, as some states/countries might require consent from both parties.)

I'd strongly suggest everyone record their phone calls with any kind of company or business, especially larger corporations. It's a good way to make sure they can't renege once they've promised you something.