Vodacom *****ing data & Airtime

For the past few days, Vodacom has been *****ing my data and airtime. This looks like it's been done on purpose as they no longer send the SMSs which shows how much data balance you have on your account. For example, I would buy 30MB for an hour then after 20 minutes my data and airtime are gone. Please check the billing on this number to see what i talking about. I recently bought 250MB just like that.

I use my device data usage to track how I use for data for in a given period but my usage is always lower than their billing.

I have been using this network as far as I could remember but for the past year or so Vodacom has succeeded increasing their sales by de*****ing their clients of data. You keep doing this !!!

My question to Vodacom is that why are they doing this to their valued customers???