Defy technical

I reported and requested for a technician to come replace the thermostate on my oven on 10 August - call out nr ***. I was quoted R720 for the call out! When I paid it was R780. On 2 September I got another call nr - ***. On 30 September I received the 3rd nr - ***. On 6 October I received a phone call from *** informing me that a technician will be there on 7 October! Well I am still waiting! Worst service ever!