Mandie and Harper JJA, Robson AJA in Saric v Tehan  VSCA 224:
The question whether to vacate an appeal fixture (or, for that matter, a trial fixture) is pre-eminently a matter for the discretion of the Court in all the circumstances of the particular case. There are no hard and fast rules. The question is to be decided having regard to the interests of justice, not only as between the parties but also having regard to the orderly administration of the Court’s business.
Notwithstanding that there are no hard and fast rules, it is well accepted that the non-availability of particular counsel cannot, of itself and without more, be a ground that would justify an alteration of the appeal date.
In the present matter, the respondent seeks to have the date fixed for the appeal vacated because his senior counsel, who appeared on the application for leave to appeal, and had been briefed to appear on the appeal, has become unavailable. The respondent submits that, as a result, he would be prejudiced if required to contest the appeal on the currently fixed date, having regard to the additional or duplicated costs of preparation involved in obtaining new senior counsel at this stage. It is submitted by the respondent that these additional costs involve an unfair and prejudicial burden particularly where, as in this case, the monetary amount involved is small.
It cannot legitimately be contended that an alternative senior counsel could not be obtained for the appeal or that there is insufficient time for that alternative senior counsel to prepare the case. Nor can it be credibly contended, in our view, that, having regard to the legal issues and the lack of any real complexity involved in the appeal, the appeal could not be competently conducted by appropriate junior counsel. We would add that, in any event, there would be no guarantee that the respondent’s chosen senior counsel would not, in the future, become unavailable for any alternative date that might be fixed.
In those circumstances we do not think that such prejudice as might be suffered by the respondent in relation to costs, which in reality is the only substantial prejudice that the respondent can establish, is sufficient to justify a change to the appeal date. The application will be dismissed with costs.
(I haven't given a pinpoint reference because the extract above is the judgment. All of it.)
In Tehan v Saric  VSC 175 the issue is whether a plaintiff in a $30,000 negligence action is entitled to damages for a loss that has since been remedied by the unintended actions of a third party. I suspect the solution will be found in equity.
I also suspect that the matter has already cost both parties more than either has any possibility of recovering.