billed upgrade admin fees even though I upgraded online

On the 14th Aug, I upgraded via online. Before the August month ended, I logged on to the internet to check my Aug bill so far. I noticed I was being the upgrade admin fees on all 4 numbers that I upgraded. I queried these but still when I received the invoices in Sept, nothing was rectified. Last week only 1 upgrade admin fee (R150) was reversed, that happened after I constantly contacted Vodacom. I'm still waiting for the other 3 to be reversed. I really don't understand why a person is billed an upgrade admin fee while the upgrade was done online.