This situation comes about because the Enforcement Authority, in this case Newham, is not routinely informed when a request for review is submitted by the appellant.
You have 14 days to submit a review request. And it maybe a further 4-6 weeks before the "request" is scheduled. If the request is granted the appeal is reheard immediately. But it can also be adjourned.
All this means that in the meantime the EA's enforcement machine carries on automatically, if you haven't paid the penalty within 28 days as specified in the original Tribunal decision. The enforcement process has not been put on hold. And can escalate to the Charge Certificate and Order for Recovery stages. So my standard advice is to submit a review request, where it is possible and to also pay the penalty, then seek a refund if you prevail at review, as you have done.
As I recall the advice to pay the original tribunal decision before any review has been heard was also on the LT website, but I can't find it now.
However Newham seem to have no procedures in place to deal with successful reviews when the decision notice lands in their inbox. Reviews are very rare and successful reviews are even rarer.
The fastest way to resolve this seems to be to email the London Tribunals, FAO the Chief Adjudicator, and copied to the Council's CEO and Chief Legal Officers. Ask the Chief Adjudicator to write to the other two to remind them of their legal duty to comply with the order of Adjudicator

? made on the dd/mm/yy cancelling PCN nnnnnnnn and to arrange immediate refund of the amount already paid.
Doing so provoked very quick responses from the Council on several occasions, followed by the money. However in one case it took over 30 days for the money to arrive in the appellants account.
rachel.mckoy@newham.gov.uk is the Director of Law & Governance - resigning in September
Paul Martin is the newly appointed Interim Chief Executive - at a guess paul.martin@newham.gov.uk
queries@londontribunals.org.uk