Kobus from Basileia Accommodation has not refunded me

Our contract states very well that i should be refunded 30 days after i put in a notice that my little sister will be moving out. So 16 Nov 2017 i put in a notice and kobus was supposed to refund me on the 17 Dec 2017 he failed to do so. when i asked him he said he would do it on the 27 dec 2017 and he failed to refund me. sent whatsapp messages and he said he is still on holiday and promised before 2nd of January. he still didnt refund me. today i called him he said next monday. But i do trust he will do it as he has been promising be will do it but did not keep his word. i signed a contract still have it.