WestJet seems to the worst for compensation, as they seem to deny even very legit claims for compensation or out of pocket expenses. Definitely want to escalate via one of the regulatory channels, as that seems to be the only way they'll pay attention (or small claims). If the concern is around standards of treatment and/or out of pocket expense, the DOT is much quicker at addressing complaints. If the only concern is the lump sum APPR compensation, you can file a CTA complaint (easy to file, but can take 1-2 years to hear back) or small claims court if you're a bit more ambitious.