Call Limit Service setup, no lock as per T & C

I setup my call limit to R50 and my account should have been locked as soon as I reached R50 usage above my monthly mobile data I receive with my contract, but this has not been done by the department responsible to ensure the lock is in place!!!!<br> I now have a bill of over R3000 which Vodacom will deduct *******ly of my bank account due to not rendering the service they offer which clearly states in the Terms and Conditions of this service that the account will be locked as once the chosen call limit amount is reached.<br> This function worked as per the Terms and Conditions and my account has been locked as per my preferred call limit setup previously, why was this not done now??!!!! All settings are in place and active on my account and no notification was received to state any otherwise, but Vodacom wants to rob me of money not due to them due to a defect all of a sudden in their service. <br> This needs to be corrected ASAP from Vodacom as I will not be held liable for an error from their side for a service which worked perfectly with my device in the past, I have set a call limit of R50 above my normal monthly contract amount and this is strictly what is legally owed by me to Vodacom