overcharged on mobile

I was overcharged four months in a row.  Suddenly, the bill jumped and consistently stayed high.  It is 100% impossible for our data usage to have increased when both lines never left the house for several of those weeks.   After my complaint, I was contacted by LaToya D.  She led me to believe that I would get a refund and gave me an email address in which I could contact her.  After two ignored attempts, she replied by telling my I am S--- out of luck.  In addition, I am unable to see call logs, which is against the law.  I am changing providers as soon as possible.