Things happen. Hassling the artist isn't going to make him or her in a huge hurry to get back to you. Just leave it. Let them get well. There are lots of bugs going around at the moment.
Also, they did YOU a favor by not making you sick. So calm down.
Just like any other job, people get sick. And then while they recuperate, and focus on health, might not respond to work stuff for a few days. Doesn't seem like a big deal.
The only way to fix wavy lines is to make them thicker. Then you have to make ALL the lines thicker so they match. You’re more likely to end up with a mess than a fix.
next time just find someone that can do it right the first time. People think that anyone can do simple things like this. It’s actually HARDER to do simple things like this because if they aren’t perfect, it’s easy to tell.