Vodacom are *******. I want my credit on my account.

Vodacom are *******. I want my credit on my account. I have cell phone insurance with Vodacom that I took the beginning of January. For the past 5 months, Vodacom has increased and decreased my premium without my consent. I have lodged complaints with their support and nothing has been resolved yet. They promised to credit my account end of April and I am still waiting. People check your invoices and asked questions.