Price lock ****

I initially had a premium contract with DSTV paying R899 plus an extra view of R80 then in September they decided to offer me a price lock with additional explora decoder for R750 plus R80 each for 2 extra views which should bring monthly instalments to R910 but for some reason they have been deducting R999 on monthly basis and no one seems to know the reason. I spent more than 1 hour of my airtime which I demanded to speak to the manager, I waited for more than 15minutes on the phone without anyone helping me .