Debit order more than R799

DPP department of Multi choice has contacted us for the R799 special. When doing all the confirming I asked the agent more than once what will the max instalment be. She said no matter what time of the month I contact them to switch me over the max instalment will be R799 I confirmed this over and over and she assured me it won't be more than R799. I checked my account and the debit order that went off was R898 how is this possible. Not happy.