MTN - Unasked for limit changes R200 ******!

I have had a recurring contract for the last 6 years with MTN the same exact 2 year contract i have renewed twice. The contract costs me R350, today how ever i get a debit order of R544? So i called the call centre this morning, Amy picked up and assisted me and told me that i had a Data limit of R200 that i depleted! <br> <br> When i first signed up the contract i got the Shop assistants to set my limit to R0! on the 15th of September at 7:11pm i get a message stating that i have stated incurring cost from my usage limit. This made me confused because i never had a usage limit before, it gave instructions as to how i could set that limit, which i did immediately at 7:13pm i set the limit to R0, so in the space of 2 min(while i was connected to my wifi) responding to a message to set my limit to R0, i ate up R200 worth of data?? - Bullsh*t! <br> <br> Note i have evidence of all this, I have all the Messages. I never gave permission to MTN to change my limit! they did it out of their own volition and without my concent. I would like to have my R200 given back to me please! The result of the THEFT of my money and breach of my agreement with MTN is now they have lost a once loyal customer for good.