Air Europa - Overbooking

I made a booking for a trip from OPorto, Portugal to Havana, Cuba. The trip was today and included two AirEuropa flights. One from Porto to Madrid (flight nr ux 1146 ) and another from Madrid to Havana (flight nr ux 051). When I got to OPorto's Airport I was informed that my flight was 1h delayed. During our flight the pilot told the passengers with connections to Havana to go fast to their boarding gates in order to not miss the flights. He also told us the number of our boarding gate in order to get their faster. I landed in Madrid and went running to my boarding gate, as I was told to. When I got to the gate the ladies working for AirEuropa (that were making the boarding) told me that the company assumed that the passengers coming from Oporto would not arrive in time for that flight so they had sold our tickets to other people. We stayed with no flight for havana, even though we got there on time and no one, until that time, told us that it was even a possibility. In fact, as said before, the tribulation for AirEuropa told us the exact opposite.