Vodacom Snatching Data & Airtime

I have a contract with Vodacom where I get R200 airtime and 250mb data every month. I normally get my airtime and data on the 1st of every month. I have wifi at work and home so I almost never use the data on my phone. It has now happened several times where I get an sms at 00:06 on the 1st of the month where it says that my data has run out. It is impossible for me to have been using my data at that time of the night, because I have been sleeping at that time, and the wifi was ALWAYS on. The previous month, the same thing happend, but that time all my airtime AND data was gone. I have sent an sms to the STOP ALL number, and it said that I am not registered to anything - but still this keeps on happening. The same thing has now happened to my boyfriend as well where suddenly all of his data was gone. He then recharged his data and immediately all of it was taken off his phone again. This is getting ridiculous. How can clients be happy with Vodacom if their airtime and data gets snatched all the time? I have posted this complaint on the Vodacom Facebook page on Sunday morning after this happened with my boyfriend, as I feel this is now getting ridiculous, and it is Monday night now, and still no one has gotten back to me. I personally feel that this is BAD service.