Failure to pay Incentive and outst Money on Price

SA Property bought house from me in August 2014 and Promised to pay an incentive of R75 000 within a month of registration of Property. They also claim that they pay cash for property. The property was Registered on 21 Feb2105 .To date they've only Paid R20K OF THE PROMISED R75k.They also short paid me on my Selling Price by R300k excl Agent fee of about R82k.<br> <br> I 've been writing mails since February for payment of monies due to me .I've written almost 7 letters to Guilame and he can'