VODACOM ****MED ME R12 672

Vodacom ****med me R12 762 and promised to reduce my monthly subscription to R886 as I had made an upfront payment however my bill is still above R1000 per month and when I call it either they say they also don't know what the issue or they will escalate my query however they don't come back to me. I would never refer this network provider to my worst enemy and once this has been resolved I want them to find a way to compensate me as their customer.