The Refuse to pay my Deposit.

I Stayed at Homii 2 Rissik Johannesburg since 2019, now that I moved out because of their horrible services they refuse to give me back my deposit. They say they do not see proof that I paid that money, I emailed them my proof of payment and I am still not not paid when they indicated that payment will be made within 20 days now the property manger says he did not receive the proof of payment at all and I have it on record that I send the email. I want my money back.