Scenario:
Company TA only books Tango. Typically I call AC and they like more money despite the rules, so I always use my own CC to pay the difference to Flex and get the miles.

I call SE line. Get this new agent who says she's never done this before. Won't touch it because it's a TA thing. Say I've done it before, she goes through up to the price differential and then says wait a second and puts me on hold. Comes back and says her lead won't allow her to touch it. I say that's fine, I'll call back and talk to someone else.

I re-call the SE line... AND GET THE SAME AGENT!!!!
Amazing. I hang up.

I call the normal AC reservations line. Get a new agent. Simple upsell. Tango to Flex, same flights, here's the difference, what's your CC, what seats do you want, all emailed to you.

Love it. "Hang up and call back" failing one time. I may have laughed out loud.

l.