Telkom spend limit ignored

I have a contract phone that my daughter uses. In order to limit any out of bundle expenditure I placed a spend limit of R 2 for the phone at the Telkom service centre. When the phone was recently ****** the ********* purchased R 2123 worth of airtime and data from the phone even though the spend limit was in place. When I complained to Telkom they told me that even though the spend limit still reflected on the account that it could be changed from the phone without my knowledge or approval. I cannot believe that I am just given an excuse like this and a bill that will be added to my debit order at the end of the month. It seems to me that I have been de*****ed twice.