Budgetair Double Charge & Bad Customer Cervice Complaint

I was billed twice by Budgetair, despite the fact that I bought tickets for a domestic flight. Now, they're requesting a passport or visa, which was not previously mentioned. Their system is seriously flawed, and it's incredibly frustrating that I can't seem to find anyone who will listen to my concerns. Who is in charge of addressing complaints, and what is the plan for resolving them? Given the widespread impact on individuals, it is quite intriguing how this company manages to sustain its operations.