Attempts to collect debt not owed: Debt collection

I am filing a complaint regarding a travel package that I purchased using financing through your company. I was the account holder and the person responsible for making payments on the loan. A passenger who was listed on the reservation, but was not an authorized user or account holder, contacted the travel company and canceled the trip. The company processed the cancellation without my knowledge, permission, or authorization. At no point was I contacted to verify or approve the cancellation, despite being the account holder and the individual financially responsible for the loan. As a result of this unauthorized cancellation, I was left with a balance of approximately $1800.00 and have been told that I am still responsible for the debt. I believe the company failed to properly verify the authority of the person requesting the cancellation and failed to protect my rights as the account holder. I am requesting a full investigation into how the cancellation was permitted without my authorization and why I was not contacted before such a significant change was made to my reservation. I am also seeking appropriate relief regarding the remaining balance and any charges resulting from this unauthorized cancellation. Thank you for your attention to this matter.