I faced the same problem, and escalated the issue contacting top executives, I finally got the call today after they received directive from their higher ups.
the solution took just 10 minutes of our time to get it resolved, I dont know why the Support Team is not briefed on this. You can try the solution that worked for me, keep me posted if it helped
1. First open browser in incognito or inprivate mode and log in to your QB
2. In QB go to your company settings and check your company address, ensure there is no special characters and symbols in the address.
3. In Phone option also no special characters, only 10 digit number
4. once point 2 and 3 is completed, click on save and done
5. Now fo back to your subscription page, change it to netbanking, update your credentials and complete the nach mandate process with razorpay
when it redirects to QB subscription page wait for 2 mins, the status of your subscription should change.
the above process worked for me
