Limit

We have a limit of R1000 on a company cell phone and for two months the bill has been over R3500 each month. When I queried I get told the limit is not guaranteed as per the T&C's. What is the point of having such a limit when the person can go over by 3times the value and nothing is triggered? Imagine if a company has 100 reps and each one goes over their limit by even R1000 - that will be R100,000 extra spend that was not expected!