OVER CHARGED - HOMEOWNERS INSURANCE

In September 2015 when I queried Standard Bank Insurance Brokers about my homeowners insurance premium being so high, I was told that I have two houses on my property. In 1995 I covered the front veranda and the back veranda on my house with thatch. I phoned my insurance company to make the necessary amendments regarding the thatch. They however, instead of amending the details of the existing house on my property, added a second house. Since 1995 I have been paying insurance for a Thatch roof house and a house with a corrugated iron roof. I requested them to refund me the premiums which I overpaid for the past 20 years and the response I got was shocking! I was told that according to legislation they only have to refund me the insurance premiums for the past 3 years. They took my money over a period of 20 years for a house that doesn't exist and now they refuse to re-reimburse me. This is dishonest and *********! I have taken all my business away from Standard Bank Insurance Brokers, doing business with people who have no moral or ethical values is something I cannot do.