Debiting Large Amounts from My Account and Not Refunding!

I have been an Outsurance client for many many years, never had problems. Recently we moved from Cape Town to Johannesburg. We called and organised that our household goods be insured during the move period. We were quoted an amount of about R6000 which we accepted. To my shock, after the move I discovered that an amount of almost R13000 had been deducted. When we called, we were told it was for the transit cover! We were definitely quoted R6000 so the agent said she'd 'launch an investigation'. There has since been many calls back and forth between us and them but the long and the short of it is that I'm still in the red and Outsurance have still done nothing to sort this out! Come on Outsurance. This is not difficult. PAY BACK THE MONEY!!!!