Unacceptable service

I reciently brought an Explor decoder from On Air they said they where a accreted DSTV agents which according to DSTV they are not, In the first place was faulty and had to be replaced, one of the consultants sales pitches was that i would have 4 channels with the extraview and pvr hd deconerd to my suprise i only have two, which means i was sold it under false pretences. Now that i have had the Explorer installed i have been in contact with DSTV daily for two weeks there is still an error E143-4 on the secondary tv which they are unable to fix they have escalated the problem to the technical department for a week now they are telling me that i have to take the decoder in for testing, I have had the HD fro 4 years without any problems. I am having a real problem with this and would like to know where i stand surly their is somethilng ******** and they should not be allowed to do this.