sick employees forced to work

I would like to raise a complaint about Spar Bel-air. I do not understand why they allow sick staff to come to work. In my recent experience, I saw one of the staff coughing horribly, upon questioning if they are alright, they told me that they haven't been feeling well and had asked to leave but was promptly told "who's going to do your job for you" by management. I don't think it is safe for customers to be served by staff that could potentially be sick with an infectious disease. I also don't think its fair or even legal for employees to be forced to work when they clearly are not feeling well. Spar Bel-air needs to be more considerate of basic human rights!