Santa Barbara Airlines

I bought a ticket with Santa Barbara for my mother 3 months ago(Caracas-Miami),we confirmed the flight 48 hour prior, my elderly mother was at the airport 5 hours earlier to check in. They told her they didn't have enough seats on her flight...and if she is lucky she can fly two days later...Unbelievable!
Why this airline is so irresponsible, and doesn't take care of their passengers?

THEY NEVER PICK UP THE FREAKING PHONE.

In Venezuela the Customer Service is a mess... But here is almost the same thing....

Esta aerolínea es pésima, no tienen el mas mínimo respeto por sus clientes. Tengo varios meses tratando de cambiar unos boletos y se me ha hecho imposible. No dan opciones, solo que el cliente pague mas y mas por los boletos.