Bad service

I believe car city service are making false promises about 62 points checks . I took my car in on 23 January 2016 for service but I was not told about worn spark plugs . on the 3rd week from service my car started losing power and when I check I found out that the plugs are worn . I called Owen he promised to replace them as he also agreed that his guys didn't replace them when I took my car in for major service . He said I must report to the branch in edenvale but when I call him he started dropping my calls saying he is busy with customers meaning I'm no longer important . I complained to their head office but the lady at complaints department promised me that Patrick will call me until now . I'm frustrated because I use my car for work but no one is attending to my complain . in future car city service is not the right car service for me even their head office is the same . You will not get any call from them what they need is our money finish and klaar . That's was my mistake I will never trust car services like that , I leaned my lesson .