Shocking service - Supplier doesn't care!

Onair Tv supp**** explora and dual view decoders and appointed an installer to do the necessary installation late in June. This was to replace an HD decoder and extra view decoder which were working perfectly. The installer was initially unable to complete the job in that he couldn't get a reasonable picture from the dual view decoder and was unable to get remotes in other rooms to work (Cat 6), thus we could not change channels other than in the room housing the decoders. The installer promised to come back the next week to sort out the problems. This never materialised. I made numerous attempts to contact the installer, but he failed to answer my calls. The installer was Astra Logistics. I then contacted On air Tv, and have continued to do so regularly for around 3 months to get the proper installation of the decoders. Three months later and I am no further in this regard. They never come back to you, make all sorts of promises, but never deliver on these. The latest excuse is that the original installer is overseas until mid October! This excuse after 3 months! What about customer service? Would I do business with them in future? A definite NO!