****** data and airtime

On Saturday, I needed my Google map to get somewhere, I put airtime and data. I had it on for all of 15 - 20 minutes, after spending 15 minutes to get the network to connect. Then it tells me I have no data or airtime.! Battery died, I was out with my data off... How did I use my data and airtime. But this is not the first time from mtn, nor am I the first person. I won't bother phoning the call centre coz you will have some nonesense that says I used it. But when you are dealing with a grown up person, not a teenager, I've had the same airtime / data package on mtn for almost 6 years, so I really am capable of knowing when I actually have spent my data or airtime. This is nothing short of **************** and is a shame nothing can be done to stop mtn from *****ing peoples money, and claiming is our fault when we know full well that it reasonably is not!