Can somone please take me serious and try to assist

About a month ago i received a call from a company by the name of on air and they were selling DSTV explorers on behalf of DSTV and i bought the decoder and i was told i also received a voucher of about R1500 which included the decoder and installation. From what i understood from the sales call was that my DSTV subscription will go up and it did go up and i had no problem, i then received a debit from the company on AIR and they saying is for the decoder, when i call DSTV call center no one is willing to assist and they telling me according to their records i don’t owe them anything and on the other hand a consultant from on air was harassing me today about a debit that did not go through, what’s the debit for when I’m paying extra on DSTV??????

can DSTV and the on AIR company meet and discuss as to why is DSTV debiting me extra for the decoder and why do i have to pay on AIR as well. Also i need to know what was the voucher i was told about for.