Randburg Service: False Positive fault diagnosis

My HD PVR (2 Tuner) DSTV decoder was only displaying about half of the channels e.g 100, 103 (not 101 or 102). Subscription was for the full service + Extra View. Phoned Multichoice: signal strength 98% on both channels - sent through various digital updates to try resolve the problem - Couldnt fix problem telephonically and advised me to take both decoders into Multichoice Randburg. Fine. Went to Randburg Service Centre last night (service ticket number 2117 at 17h54 on Thurs 12 Feb 2015) and was advised that both decoders were faulty. Multichoice Randburg Service Centre swapped the My HD PVR (2 Tuner) DSTV decoder for a refurbished one and charged me R510 - a willing purchase at the time as I thought I had discovered the fault. Alas when I reconnected , the same problem persisted - REFIRBED DSTV decoder was only displaying about half of the channels e.g 100, 103 (not 101 or 102). So now I am out of pocket R510 and have been given a false diagnosis by Multichoice Randburg. Will call a technician to check dish today, Multichoice Call Centre said I would need return to Randburg to reclaim R510 false positive fault diagnosis. Dont have time for this. Please refund R510.