Cancellation tests after revoked license

So my license was revoked as I got 6 points within 2 years of passing,

When I came to book my practical test again I had to ring up DVLA because you are not allowed to book online after having a revoked license,

I have downloaded Testi and check the website for cancellations constantly to try and get an early test date but when I apply for any date is says failed.

I was wondering if I also cannot change the date online too? Or is it due to people just booking the tests faster?

Thanks for any help :)

Edit : I messaged DVSA on facebook and they came back saying, if my full license was revoked then the system will recognise it as passed before, which they can then remove this restriction and allow you to book online.

I'm not sure if this also applies for managing my already booked test, but I shall keep trying to apply for cancellations now and see.

Edit 2 : With the restriction lifted on my license I got a cancellation test within 30 mins for next week! Just got to pass it again now.