Data Contract : R1 Spend Limit Set but still Paying Over

Hi All, I called in a couple of months ago requesting my data spend limit to be set to R1. I also called in just before the 20th to ensure this was done as I got an sms showing me I will be debited more than what my premium was. The agent told me this will be forwarded to the team lead to rectify this and if anywhere in the call there was an agreement between me and the agent to set my spend limit I would be refunded for the months I paid over.