I want my money

Greetings. My name is Mbongiseni Ngubane. On 2019-10-02 my son and l attended a property investment presentation, that was conducted by Property Coach (Carlos I then decided to register for their programme, which was R15 997.00 for two people. I paid R10 000.00 and the balance of R5 997.00 was supposed to be paid before the commencement of their programme on 2019-11-23. On 2019-11-11 I contacted them, telling them that my son will no longer be attending. On 2019-11-23 I attended their first session. And it was not what I had expected. Hence, I informed them that I am no longer interested; I will no longer be attending their sessions and I requested that they refund me. They have since then refused to refund me - stating that they cannot refund me because I did not pay the full amount. All I want is to be refunded.