Deregistration and refund

Hi, on the 11th of January 2020, I enrolled to study for a CELTA Certificate (20days) from 13January2020 to 7February2020. I attended from the first week, however on two conservative days on the second week I was absent due to family problems, on Wednesday I went and attended the full day however on Thursday I went back to tell them I want to deregister of which I was told that I had 3 options, continue with the course, withdraw or either way you won't get refund. What I what to know since I was registered for 20days but attended 8, am I not entitled of a refund for remaining days and is what they doing legal, and what are my rights in relation to deregristration and refund.