their phone calls (presumably without consent which is illegal in my jurisdiction)
IANAL, but if the call starts out with the standard, "Please note that this call is being recorded for training and quality assurance purposes", or similar, then you are free to record that conversation and it would not be illegal. All parties to the call have been informed that the call is being recorded, and thus no wire tapping laws have been broken. This works for both 1 party and 2 party states as far as I'm aware.