At first, the ground crew manager came up to the passengers asking for volunteers to change to another flight ( they would fly to Santiago de Compostela instead, and have a bus waiting for them to take them to Porto, and all they offered was a 500€ compensation, which is much less than what they should actually have to pay every passenger if no one took the offer and they had to refuse entry to passengers) as they mismanaged and overbooked this flight (even though they kept insisting on that it was an aircraft issue and they had to use a smaller one, while the people at the check in desks said clearly that it was overbooked).
After that, the boarding process took ages, as some people had their passes invalidated due to the mentioned overbooking issue, meaning their seats (mine included) were unavailable. What's funny about this is that even people in rows as low as 10-15 or so had their seats invalidated. Anyway the boarding process took well over an hour for the lucky ones, all the while the ground crew was being extremely rude to people that didn't yet fully understand the issue, instead of explaining what they were trying to do to solve the issue ( we passengers do not care how your worthless service screwed up the bookings, do not belittle us for not understanding what stupid excuses you make).
Now for the unlucky ones that had their seats invalidated, we were put to the side while they tried to figure out what to do, all the while the ground crew kept insisting for us to take the 500€ and go on another flight or whatever, which I find extremely distasteful, knowing that all of us should be compensated much better had we been refused entry. Some people that were put to the side still accepted the offer, which in the end did make room for everyone else on the flight, after of course another hour or so of waiting.
Now with all that said, I wouldn't have minded the issue as much if it weren't for the rudeness of the ground crew, the almost 2 hours of keeping us in the dark about what was going to happen to us, and the presistence of the ground crew manager to have us go to another flight, if you really wanted that to happen offer something better than just 500€, you know very well the compensation the airline would have to give us had we been refused entry.
To add insult to injury, when at last the flight took off, we weren't offered ANYTHING at all in flight, not one measly bottle of water or a bag of chips or a small cup of coffee, nothing, absolutely worst customer service ever.
As a bonus, the cabin crew hit my leg with the food/beverage cart while I was sleeping, admitedly I had my leg on the corridor, which I hadn't done on purpose or willingly, but instead of waking me up to move my leg, they just hit it and all I got was a "Oh sorry sir", then the attendant moved on like nothing happened.
It only hurt for a bit, it's not like I want monetary compensation or anything for that, but yeah a cup of coffee could have made it up for almost everything, but in addition to the clusterf*ck that happened in the ground, not even hitting my leg with the cart was enough to have a little something for all of the trouble they caused.
Worst airline I used so far, don't recommend it, I certainly won't be using it ever again.