Copa Airlines complaint: Lack of information

I have been planning on traveling to Montevideo-Uruguay with my boyfriend and our pet. I wanted to make sure I had everything I need. I purchased out tickets and then my oet’s ticket. I asked what was needed to travel with my dog and the lady insisted that I needed to check the website. I did . I purchased the perfect sized carrier , I took her to the veterinary to get her a health certificate and her vaccinations were updated . I called Copa Airlines 3 times to verify if that’s all I needed. They said thats all. On Dec 24th,2022 we were leaving and they didn’t let my pet fly with us because I needed a stamp by the CFIA to make the health certificate official. This info was never mentioned to me in all my phone calls nor in the web . Everything was closed that day and I couldn’t go get the stamp( BTW the veterinary didn’t have this info either). The lady from Copa told me that my option was to leave her with someone who can get the stamp, request a refund and change her flight for Monday. I just had to get a different carrier and my dog would have to travel alone unless I knew someone who was going to Uruguay as well. I had to call my friend to pick her up. Now Copa airlines doesn’t want to give me a refund and they keep hanging up the phone when I call. The y do not let me talk to a manager and they even said I used the ticket already . They won’t solve this issue. I am so disappointed!!!!!! My baby had to stay home alone , I’m lucky to have a friend who feeds her. But she’s sad and spent her 1st birthday far from us. We haven’t been back here in 6 years . Copa ruined our vacations. I spent a week making phone calls to get nowhere . This company sucks !.