Charged for a service I didn't use

I am writing to express my deep dissatisfaction regarding a contract/account that I have not used, yet I am now being charged for. This situation is extremely frustrating and unacceptable.

I did not make use of the services under this contract, and I do not believe I should be held financially responsible for charges related to an unused service. I request a full investigation into this matter and immediate clarification of the charges. If this is an error on your part, I expect a full reversal of the charges and confirmation in writing.

Please treat this as a formal complaint. If this matter is not resolved promptly, I will be forced to escalate it to the relevant consumer protection authorities.

I look forward to your urgent response.