my monthly data is finishing without me using it

For the past number of months the data that is included in my contract gets loaded on the 1st and by the 2nd of the month has completely vanished. I have turned all apps off and done everything anyone has suggested in making sure nothing is quietly eating my data yet I can sit and watch it disappearing within a short time without being able to do anything about it. I have tried a number of time to complain about this to Telkom Mobile but they insist the problem lies with my phone and refuse to do anything about it or to even enter into conversation about it. IF they're correct and it is my phone well then why have they not changed my phone!?<br> However, I am certain it is not my phone as this only happens at the beginning of the month when I get my new contract data automatically added. I am so tired of being treated like a fool who does not understand how smart phones work and I am so tired of having totally senseless responses thrown back at me. I am tired of having my property ****** and being powerless to do anything about it. I am angry and frustrated and annoyed and quite frankly ready to get some legal advice on this matter to be able to take it further.