Shaw Academy bad service

I am very disappointed with Shaw Academy. They advertised 4 weeks course for free but what they didn't say was that you have to pay for each level AND pay to earn the certificate. I entered my payment details and paid to go to Level 2 which I don't mind but after I completed Level 2 I said continue to Level 3 and whoops! there they took ANOTHER R500 from me without asking for authorisation. I send numerous emails to them but no one answers my email. I requested a refund as I didn't authorise payment. They are very quiet where they used to send me updates/reminders. What should I do about this as I feel I wasted R500. I completed Level 1 and 2 without any certification as I still needed to pay for that as well and wasted my R500 which I refuse to have lost as I don't want to proceed to Level 3. Please can someone make any suggestion? And be awake when you do online courses!