Price charged differs to Website

According to our invoice we purchased an AEG37699MD Gas/Electric stove from Hirsch's for R11 800. An AEG 37699MO-MN stove was delivered. On checking the Hirsch's website it was listed as R11 209.99. When contacting the store on the 21st we were informed that they would come back to us but they did not. We contacted them again on the 22nd as the installation crew had arrived and we were informed that the website shows discounted prices even though it does not state that it is discounted and that the actual retail price is what we were charged. They told us that the model number per the invoice is the same as what was delivered but is recorded differently on their system. We were also informed that we should be happy as we received a 16% voucher on the purchase of R11 800 and we therefore paid less than the website price. We would rather have the voucher reduced and calculated correctly on the lower price. This appears to show that Hirsch's advertise prices as standard on their website and claim that they are discounted when applying their 12 days of Christmas sale discount.