Vodacom chooses work permit over permanent residence document

My father went to open a data contract with Vodacom on thursday 31st August and 4 days later,the status of his application is still pending because he doesn't have a work permit but he has permanent residence document issued by home affairs which by default should override the work residence. The sales person who assisted us was very helpful and even called the accounting department and spoke to a supervisor but they all seemed not to understand and continued to request a work permit saying "their rules only take work permits and IDs.I just don't get it and need vodacom higher-ups to explain the reasons. if banks can do it why can't they.