Breach of contract - Be Aware of Regent -

We have a Nissan Sentra insured with REGENT since 2006.Only claimed for a windscreen.Our insurance premium was R192 & went to R300.00 without notifying us.We have claim free bonus where our premium decreases.When I phoned the insurer to find out that they've placed car back to market value R18000 since inception.On 29/12/2014 our car was ******. Investigator was sent to our house for questioning told us he will have car removed from the pound.Weeks later we received a call to ask where the car is.You can never get hold of Regent people.Lines always busy you're being transferred from pillar to post or they never call back.This has been going on forever.The 17/02/2015 my husband got a call that car is at Panel beaters.24/02/2015 received a call from Lucy & Craig from Regent,only to tell us that they'll only pay R6000 to fix car.Nowhere is this stipulated in our contract that this is the max amount.Asked him why & he told me it's an old car & they've put car back onto market value of 8 years ago which is R18000.Paid a premium of R300.00 which they didn't tell us why.Excess is R2000.Husband working alone & I'm a housewife. I EXPECT THEM TO PAY FOR WHAT THE CAR WAS COVERED FOR?