TAKEN 5 GB OF MY UNUSED DATA AND IGNORING MY EMAILS

12GB of my data was supposed to carry over like it does every month yet they took it upon themselves to take 5GB of that and just carried over 7GB instead of the 12GB that was left over. I have written to them several times with absolutely all my details and explaining this to them in simple layman's terms but they just ignore me, This is the case number in case someone out there cares [#***] If I get no satisfaction, this will be the last time I will deal with them!