Bad Service Delivery on Guaranteed Goods

bought a Bosch free-standing cooker / oven on 06 June 2015. Could not get the gas grill to function correctly. Tried sending an e-mail to the vendor at the e-mail contact address supp**** in the appliance guarantee booklet - message bounced back as e-mail address not existing. Searched for Bosch appliances on Website and tried to send another e-mail to the vendor via website contact address - nothing happened. After a week I phoned the contact number on the website and required about the e-mail i send previously - the e-mail was never registered. I requested a telephoninc service call log and was given a BJ010693 reference no with a promise that a technician would call me within 24 hrs. Waited another week - no call. Phoned again this morning 29/02/16 at 08h15. Was promised again that technician would return call within 1 hour. It is now almost 5.5 hrs later - still no call.