there's so many unknown if you want to chance it. Missed flight, cancelled flight, illness on day of travel, then it's a bit late to sort out all for the sake of getting the extension. 🤷
When approved, the "visa" is the permission to enter within 90 days. On entry you receive 60 day stay as a tourist. You can extend that by 30 days. Keep trying other banks. . Foot slog!
because he maybe thought the "visa valid for 90 days" was how long he could stay. But it's not. It's valid for 90 days to use for entering the country.