Hi Anderew, welcome to Microsoft Q&A :)
Congratulations on your business success! However, I must tell you that the public community cannot directly help you with your billing issue, which requires PII (Personal Identifiable Information).
According to Which Azure support option is right for my question? - Azure experience for founders - Microsoft Learn, I bet the best option for you to get appropriate support is to open a support ticket at Azure Support Options.
I hope your problem will be solved soon!