Telkom stole my day data

Hello Peter Please help me resolve a data consumption dispute with telkom. I have just spoken to Henrieta,a service call centre consultant from telkom.I have spend R 280 buying 2gig of data plus a bonus 2 gig night surfer.I work in Ventersdorp where telkom has no coverage,instead my connection goes roaming automatically,meaning that MTN was charging me day data between 12 and 7 instead of night data.I now sit with a useless 4051 megabytes of night surfer data that I cannot use. Please tell telkom to refund my day data that they stole at night while I was under the impression I was consuming night data. They must do their best to educate their consumers.