I haven't dealt with Twitter recently but recall the time when they gave me advice that was opposite to their website (during the AAdvantage phase out). I had to send screenshots to get them to finally correct their answer.
In terms of phone support, I believe it's all work at home Canadians but there's always a chance it could be outsourced. I've had my share of bad agents, although they tend to be half-decent when selecting 2, existing flight only reservations rather than 3, new flight reservations.
But like you, there's cases when I know more than the agents, which made my call relatively useless. I wanted to credit by ticket to Delta but needed to have my WestJet Member ID on the booking for the free bag. The rep didn't know how to answer this one at all.