Poor service

July this year I upgraded from Compact to DSTV Explora Ultra which means the decoder itself must be changed and I'm gonna be on Price lock which is R599 per month,ok. From the 1st month that is August I was charged R788 asked why they made a story , following month it was changed at least that means September. Beginning October I app**** for my Credit Report was puzzled to find 3 Decoder accounts on my name which it says I'm paying R99 for each so that means I must pay my compact R410 plus 297 of Explora ultra Decoders, I sent an enquiry on their Facebook pages they insist that I have 4 decoders and only 1 is active, I explained to them the situation of what happened during the installation process- they sent 3 installers of the same product and I sent other 2 back , which I believe they were sent by Vincent Sattelite office I even informed their manager immediately of the incident and she agreed only one person should install the new package , now it comes back to me that they didn't receive the package which I even gave them the contact details of 2 guys that I sent back,I'm living In a 2 rooms house, how is that possible to have 4 decoders,Now my credit record looks bad as I'm owing DStv 4 account amount to R7900,and now my instalment expected is R916 ,