******* Billing & Overcharging

My phones data was loaded on the first of Feb that includes 120mins with 2GB data & 2GB Night owl data and is then set to automatically softlock when data and the R100 call limit is reached. Yet strangely this month, by the 10th to be exact my phone gets a message after midnight stating that the data has expired and my phone has been blocked. My husband called to query the fact that the number already had an outstanding bill of R1436.63 and the agent said the phone went over the limit with R336.63, we wanted to know how it goes R336 over a R100 LIMIT ???? how this is possible for the first time by the 10th of A month as I hardly used the phone AND the house has WIFI. The agent could not answer this and when my husband requested to speak to the manager we were told he is on lunch, take note the call was placed just before 9PM ?? the agent said that the manager would call us back but up to date and time no one has bothered to call back. How do u over charge a customer who has NUMEROUS accounts with you and just block a phone without the valid sms warnings and valid reasons. This is both ***** & THEFT and this matter will be taken further in the media !!!