Hi, try the following steps:
1. Download WhatsApp Business to your phone
2. Ensure you grant WhatsApp Business all permissions before attempting anything
3. Proceed with the normal registration process of WhatsApp Business
4. Choose verify by call (voice call) on the verification step.
5...
There is one VoIP provider which provides once off paid service and you get to keep the number for life. You may choose local dialing code such as 010, 021 etc or national codes like 087, if there is a need, you can port-in your existing VoIP number. Their website is https://speedconnection.co.za
Skype is so 90s:):):), get a mobile landline (VoIP) to make cheap local and international calls. There's a company called Speed Connection they offer once off payment on VoIP landline, I'm not sure if they still do, but check them out.