Worst Service Ever!

We made arrangements with this company through a link on one of the airports website. Thinking it was a simple way to make our transportation arrangement, but I was wrong! We at least were picked up in Barcelona, but because we didn't ask for carseats reserved (even though the reservation listed the ages of our children), the driver was rude and nearly would not take us. This reservation was pre-paid for both transportation from the airport and then back to the airport once we returned from our cruise. He took us and dropped us off at our hotel and it ended up being ok. Once I got connected to the internet, I contacted the company to be sure we had carseats for the return trip to the airport. I was even charged extra for those - ok, fine. But then when we needed to be picked up from the port (which was listed on our reservation), no one showed up. We called the numbers listed for the company that was to pick us up and never got an answer - not even a voicemail to leave a message for someone. We called multiple times and waited for over 2 hours for someone to show. we eventually had to pay AGAIN for a taxi to take us to the airport. When we got back home, I contacted the company and they said there was nothing they could do. ABSOLUTELY HORRIBLE CUSTOMER SERVICE!! DO NOT USE!