To finish your sentence: in the same type of employment contract. Changing the type of contract vastly changes what is on the table.
Hiring employees in South Africa is a large risk due to the labour laws which make it very difficult to get rid of useless people. You can mitigate that immensely for a potential employer if you are willing to go on a fixed term contract at a higher rate. If you are confident in your abilities and work ethic, you will know that after that fixed term contract, your employer won't easily be able to replace you, so you will be in a vastly stronger position with the increase already included. However that means that you have to take a risk.