Bad Service

I changed my dstv package from having an extra view decoder to 1 compact and another decoder as access subscription, today I'm being sent from agent to team leader and no one can answer why my billing is incorrect and why my access subscription was not activated on the 1 December 2022 and was only done 28th December, I had to pay R200. 60 today whereas they deducted R798 in December, when I ask why I am told that I had an outstanding amount of R120 from previous month, when I ask how this happened as I am a debit order paying customer and have never missed a payment and why I was not informed about this, they opted to lie and say they'd investigate and call me 1st thing this morning, no call till 12:45pm. My balance to be paid 25th of this month is R798 again and there is an access subscription included, why am I paying for the same thing twice?