Involuntary bumped departing from foreign location

Question about compensation for involuntary bumping. We had a reservation from Cape Town to Atlanta on Delta for family of 5. 3.5 hours before the flight on the way to the airport we had not checked in and we were involuntarily rebooked for 24 hours after our original flight. We were never even notified of this- we noticed when we were trying to check in. At the airport Delta said we were bumped because the flight was diverted to MIA then ATL and additional crew were put on the flight and they were given our seats. We asked to be put back on that flight (any seat) and were denied. We were offered no compensation even for taxi or lodging. We don’t even know if the airline asked for volunteers to be bumped.
On our original flight we had 5 Comfort Plus seats together and on our new flight we were given 5 middle seats in main cabin not together. The only thing we’ve been offered is a refund of what we paid to upgrade to Comfort Plus.
I am wondering who had guidance on the best way to get compensation both for the expenses we had to incur plus the terrible inconvenience, including significantly downgraded seating.
I see from Bumping & Oversales | US Department of Transportation that we may not be entitled to compensation because it is a flight departing from a foreign location, but does not feel fair.
Thank you for any guidance.

If you have a twitter account of any size (but it works better if you have followers), I’d suggest a public post there tagging Delta.

I think the best solution is to post on Flyertalks Delta forum. Frequent fliers there have a lot of suggestions as to whether you are entitled to compensation and how best to get it. Even if you are not entitled to compensation, there may be suggestions on how to request it anyway. Certain situations, your status or just the way you ask may make a difference.

There are forums for all the airlines, frequent flier programs, destinations and ways to get points and miles (seriously that forum is called S.P.A.M. [Sites with Points and Airline Miles]).

The most effective tool I have used in situations like yours is to threaten to take my case public. The first rule is to be honest, respectful and stay calm and reasonable. The second rule is to be doggedly persistent.

I start with the first level of customer support and make a simple request. When that is rejected, I first ask for their name and explain to them that they are forcing me to resort to pleading my case to the public and tell them that my hobby is making videos for social media and have some with over 500K views. If they persist in their refusal I ask for their next level of customer no-service.

From there I just escalate up the line until I get satisfaction. The people you are interacting with are evaluated on solving the issue at the lowest level. Be a loud squeaky wheel with a convincing and reasonable strategy and you’ll usually get an acceptable solution.

I’ve had good success filing complaints with the FAA. Though I don’t know if it works when the flight originates outside the US, it is a US airline. So, you could try that.

I had an issue with Hawaiian air once. Talked with customer service and got nowhere. Put stuff on twitter and they contacted me following that but got nowhere. Filed a complaint with the FAA. Several weeks later I got an email from a case worker from the FAA that was going to look into it. Within 30 minutes after that email I got an email from Hawaiian Air refunding me all my money.

UPDATE - I did receive several recommendations of steps to take from Flyertalk. I opened a case with DOT (no response yet after 2 weeks) and sent a copy of that complaint to Delta Customer Service.
Delta 1st response was that we had rebooked our flight on the self-service app or
I responded back to Delta saying that my wife and I are convinced that neither of us did that. We were told by the agent in CPT that Delta Global rebooked us.
Delta’s next response was to provide a $150 voucher per passenger for the inconvenience.