If you’re having trouble requesting a refund through the digital games refund page, I would normally guided you to contact Microsoft/Xbox Support next. Please note that, for digital purchases, Microsoft offers a refund policy where refund requests are usually reviewed within 14 days of purchase and fewer than two hours of play. If you receive the error 'Request is blocked', please try using a different browser or use incognito mode and see if you can access that page.
However, since you’ve already gone through your bank, the refund process will now be handled directly through your bank.
Meanwhile, I recommend reviewing the article below, as repeated misuse or abuse of chargebacks can be considered fraudulent according to Microsoft's policy.
Best regards,
Gunasekar N