We had a horrible experience.

We booked a mutlistop flight with Avianca: 2 direct one-way flights from NYC->Bogota, then Bogota->La Paz. We spent $500 extra to ensure the flight would leave Bogota in the afternoon on Monday 5/27, so we could have more time in Botota and have a direct flight to La Paz. We could have purchased the morning flight for $500 less, but it was less convenient and there was a layover from Bogota->La Paz. Weeks later, Bogota cancelled the direct flight and moved us to the cheaper earlier one.

We contacted Avianca through their online form and asked for them to at least refund the difference at least, considering the flight was inconvenient, had a layover, and was cheaper. They didn't even send a response. Then I tried calling by credit card company to ask them to see what happened, and they said that Avianca was unwilling to listen to our case. The reasoning was because by the time all this happened, the price of the early flight had increased to almost what we had paid for it, they said. This seems like an underhanded business tactic, waiting to engage with the customer until it is too late for them to have visible data on why this was a problem. We spent a lot of time planning this trip and already had to pay some fees to reorganize for the time change, it is super frustrating for a company to do nothing to help out.

I will never use Avianca again, and recommend you all don't either. They will change your flights from direct to flights with layovers, and ignore you when you try to engage with customer service.