They were. They objected to the US flying them back in cargo planes and requested that they be sent5in passenger planes. They then offered to fly them back at their own expense using their own planes, and Trump responded by pretending they were refusing to take their citizens back, and imposing this knee-jerk 50% tariff. This was all about grandstanding and making a show out of these unnecessary tariffs that will end up significantly raising the price of Colombian goods—primarily coffee—for the American people.
Discussion
It appears that Colombia have caved
Dishonest miacharacterization. They didn't "cave". Their initial issue was that cargo planes were being used to transport people. That's why they offered to use their own planes at their expense to fly the Colombian migrants back home. Now, they US has agreed to use US military planes configured to transport personnel, which is all Colombia wanted in the first place. No rational person could look at the details of this situation and say Colombia "caved".
I can't find anything suggesting that has been agreed to.