Unexpected expenses

I canceled my wifi plan in the beginning of January (after monthly payment) and returned my box with no issues. What I didn’t realize is that they failed to provide the information following breaking the contract early. I suddenly lost my living situation and was forced to move out meaning I no longer needed services. At the end of February I received an email stating the outstanding balance that accounted of 10 dollars for every 19 month left in the contract. After talking to the same store I signed up and canceled with, they assured me that I could pay the balance off over a few months. As of today going into March, I received a bank statement followed by an email that the full balance was pulled from my linked account with no warning whatsoever. I am very disappointed with the communication throughout the whole process of my service which leads me to believe I will not be returning in the future.