Vendor questions

First off I am so happy I found this website, and second long post warning! It's helped so much. So I am a little frustrated right now. I am getting married on 10/10/2020, and have hired my videographer. I paid deposit have a signed contract from BOTH parties all that jazz, and mind you on the contract as you guys know it has the time frame we both have agreed to. Well I am apart of a bridal group on facebook for the metroplex and surrounding areas I'm in, I saw today a bride asking for a videographer on my same date ( Yes I know it's popular) and the same time frame, then I see my vendor commenting that they have that date available. Keep in mind they are a two person team, no assistants or help, and they both are doing my wedding. So I messaged them and in a nutshell they said that with the craziness of the holidays and having a pet recently pass away, and looking at the wrong month on their calendar, it didn't click with them that it was the same day, they reassured me they would not give my date away and they deleted the comment on the other bride's post. My fiance and I are paying for this out of our pocket with basically no help, so I am worried we are going to pay all this money and they not show up. So, My questions are this: 1. How should I handle this? Am I overacting? I have not been rude at all and am trying to be understanding. I am obviously new to this whole wedding planning stuff and don't know much about vendor issues like this, so any help is appreciated!