This may be of general interest - I have promised one of our students to investigate and now I can't find the email to reply individually. On the RHS portal it now states:
Learners that were enrolled on the June examinations have now been automatically transferred to the corresponding September dates, however, they may defer to the February 2021 session at no additional cost. Learners are asked to contact their centre to discuss such arrangements.
I think this will only apply to students previously registered for June, and the deadline for deferring from September to February without paying for the exam is still going to be 24th July, to allow us to make changes on the portal before the the RHS booking cutoff.