No payment after work was done

Never do anything for this company before you get full payment. I have done Design work for Mr. Build Tzaneen more than a month ago. It was a very urgent Job and i spent more than 10 hours on the artwork. It has been more than a month and I am still fighting for payment. Now they only want to pay R500 of the R2000 invoiced. All artwork was approved and I even gave them the open artwork like they requested. My messages are being ignored and still no payment. VERY VERY BAD COMPANY TO WORK WITH.