Video calls won't work!

Hi. The video call quality on my Macbook Air (2014) is outrageous. I have an excellent internet connection, download and upload speed are great, I'm the only one using this connection. Still, I cannot do a videocall that lasts longer than 2 minutes because the quality of video and sound is crappy. I paid this computer A LOT of money and I'm having issues with it all the time regarding video-calls! I've checked on another 2 computers, it's working normally!

What is the problem? This is wasting my time and money! Where can I make an official complaint or get a substitute/new laptop? This is the computer I personally paid a lot of money and I'm using it sometimes for business video meetings and it works for 5 minutes and then drops the quality. I cannot afford these situations. The reason why I purchased Macbook 13-inch was because I can use it for occasions like these, but the crappy thing DOESN'T WORK RIGHT!