Part of the reason you haven't received an answer to this yet is because it's in the wrong category. This isn't a question of legal ethics, it's a consumer issues. Thus, I have recategorized this to get the attention of the kinds of attorneys who will have an answer to your inquiry. (I am not one of them, so I won't hazard a guess.)
Answers to legal questions are usually fact-dependent; my answers are general and based on the facts as you describe them and necessarily includes assumptions. More specific answers can be provided only after researching the appropriate law and a comprehensive consultation in which all relevant facts are disclosed. Until both a retainer agreement is executed and we have a consultation, I am not your lawyer and you are not my client. Moreover, I cannot be your attorney unless you are located in Missouri, the only state in which I am licensed. If you are not in Missouri, please consult an attorney in your state for assistance, as my advice may be incorrect or incomplete. This uncompensated answer is provided for informational purposes only, as a free public service; any reliance thereupon is at your sole risk.
Maybe. It is possible, however, that your agreement you agreed to when you initially signed up for services explicitly states that you agree they may do this. Even if it doesn't, however, unfortunately it will be economically unfeasible to pursue the telephone company as an individual claim. What is the interest you lost on $100 for 3 months? No attorney would want to take that case as an individual claim unless you were going to pay their hourly rate.
Your best bet would be to get the interest of an experienced class action attorney. However, the first thing that attorney will want to see is your initial agreement with the telephone company, so be sure to have that ready to send.
The answer given does not imply that an attorney-client relationship has been established. Your best course of action is to consult with an attorney by phone or personal meeting. Contact your local bar association for a referral.
I agree with Mr Wandes. Economically, your claim is only feasible as a class action. The terms of your agreement with this company will determine whether there is a viable class action lawsuit.
Legal Information is Not Legal Advice My answer provides information about the law based on the limited information provided in the questions asked and is not intended to provide legal advice or opinions, and does not constitute an attorney-client relationship. The answer to the question is for educational and informational purposes only. The law differs in each jurisdiction and may be interpreted or applied differently depending on the jurisdiction or situation. Accordingly, I highly recommend that you consult with an attorney to discuss the details of your problem so you can get legal advice tailored to your particular circumstances.