@Samantha188 - From the form itself:
Do NOT use this form if:
• You are NOT an individual . . . use: W-8BEN-E
• You are a U.S. citizen or other U.S. person, including a resident alien individual . . . use: W-9
• You are a beneficial owner claiming that income is effectively connected with the conduct of trade or business within the U.S. (other than personal services) . . .use: W-8ECI
• You are a beneficial owner who is receiving compensation for personal services performed in the United States . . . use: 8233 or W-4
• You are a person acting as an intermediary . . . use: W-8IMY
Note: If you are resident in a FATCA partner jurisdiction (i.e., a Model 1 IGA jurisdiction with reciprocity), certain tax account information may be provided to your jurisdiction of residence.
Tax help can be found with a tax professional, which I would encourage you to seek out in South Africa. The community forum is made up mostly of other hosts, some of whom have tax knowledge, but do not have specifics to your situation. Your hired accountant certainly can help you.