Will I have to send the computer in to get the card exchanged or is it an easy fix? And also are there any cheaper upgrades that could still work? Sorry about the trouble.
Expect to pay ~50-100$ on a low end graphics card that can run Magicka. Since you asked if it's an easy fix, I'll presume you don't have too much experience around the inside of computers. There are tons of guides and websites that can walk you through changing your GPU. If you're uncomfortable with doing that since you could harm your computer, call up a local computer repair shop and tell them that you want to replace your GPU and would like them to install it. They may even offer to order or sell you the GPU, but you'll pay a little more then. Websites like tomshardware.com have reviews on low budget cards and tons of forum threads about them, browse those and decide which GPU you'd like and price it on newegg or amazon, find a good deal and order it, in less then a week you'll be able to play.