No one insulted you. They commented on the fact that you don’t understand reality for most people. Most jobs are so easily replaceable and have so little protections that if you start citing laws and taking sick leave like it’s rightfully yours, you’ll be fired a bit later for “unrelated” reasons.

Thus while you are right that you would be able to get your sick leave by communicating the law, you will not really get them because you’ll be out of work in a few weeks. If you want to keep your job, you don’t communicate the law and don’t take your sick leave.

Btw, unionize to prevent all this.