Contact
One address, read by a person. There is no ticket system to navigate.
Support
[support@yourdomain] — billing questions, refunds, a classroom that will not grade, or an organization nobody can get into. We aim to respond within 3 working days.
For a grading problem, the fastest thing you can send is a link to the submission page for the run in question: it carries the commit, the status and the full test output, which is usually the whole answer.
Registered address
[Registered legal entity name]
[Registered address, city, state, PIN]
India
Tax
GSTIN: [GSTIN, if registered]