Account locked and limits not honoured

It started off with me trying to make a call only to find out my services were suspended according to the limit I had set on my phone. I sett a limit to protect me should my phone get a virus ore something crazy that would eat my data. I am diligent at topping up my data when needed and usually do this every month. So I phone 082111 to increase my voluntary limit by R300 to unlock my phone which they did. Immediately I get a message saying my phone is locked. I call back (082111) the lady says my usage is just over R1300 to which I say this is crazy and the reason I put limits on my phone and moan saying asking why they didn't honor the limit I signed up for she told me to read the terms and conditions etc. I then increase my limit and my phone is unlocked at home while connected to wi-fi. I buy a 1gig data bundle and make 2 quick calls i get a sms that my phone has been locked. I call 082111 and the consultant tells me its been locked because my usage is over R2400 its increased by over R1000 in 5min? The worst was that when I tell the consultant something is seriously wrong she says no the consultant i spoke to before didn't check properly. How did it get unlocked if she didn't?