Consumer battle

It's just about 2 years now that I bought a Nissan np200 from Nissan menlyn, I've been struggling to get my spare key which I'm intitled to since this was a new sale, other then that I been sending emails to the branch for a service extension since I use the bakkie for business, recently I took the bakkie in for a service and the were parts that were not changed Even stated on the job card yet no 1 has communicated with me as to what should be done. I'm wasting time energy and money trying to get this Nissan mess sorted out but it seems to be falling on deaf ears. I'm gradually loosing trust in this brand