Go to Settings → Credits. You'll see:
- Current balance, split into subscription credits (expire each period) and top-up credits (never expire).
- Usage history, an entry for every generation (with the type of content and when), every grant (renewal, bonus, top-up), and every refund. Deductions link back to the job that consumed them, so you can see exactly what each generation cost.
If the numbers don't add up for you, for example the balance dropped without a finished asset in your Library, check the history for an automatic refund entry first (failed jobs refund themselves), then message support with the date and we'll trace every entry with you.