SARS says I am owing

Good day

I went through my e-filing system and I found out that I am currently owing sars, I do not understand how because I am an individual who is currently unemployed. My previous employer have been paying my taxes and now sars says I am owing the R4700, How is that possible? Regards Siyabulela Godfrey Tsosoana ID:*** Contact number:*** *** ***