Mo'nice data expiring long before it's supposed to.

I bought a 6.84GB Telkom Mo'nice data bundle on 7 June. It's supposed to last 13 days(but it's actually 12) and that expires on 19 June but now I'm seeing that my data expires on the 13 June- actually 12 June, midnight. Telkom is clearly cheating and *****ing from its customers.