Regret signing up for multi-year lease

Been with Netstar for more than 10 years, decided to signup for a discounted multi-year lease package a few months ago, and have regretted ever since because of poor account management.

I was double charged on 1st month, then charged full price on 2nd month, and 3rd month I was charged more than the discounted price. Overcharges have still not been reversed. To date I've paid more than I would have, had I just stayed with the month-to-month. Emails aren't solving the issue, Netstar communication terrible/non-existent (just generic auto-replies).