Burnard, Raaff & associates - extremely poor service

A dispute re my vodacom account resulted in it been handed over to Burnard, Raaff & associates. I paid the account in full but cannot get a signed, valid receipt out of them. After numerous emails, whatsapp and calls to consultants 5 and 11, (SANTIE IS CONSULTANT 11), nothing happened. How do I get the business to issue me a receipt?.