You could try this, SPServices is wraped with soap service.
Because the update is unavailable, you will need to patch your current farm to a higher patch level (if that is the last update you've applied, you should be applying this months patches to prevent a potential compromise of your farm). I would suggest applying the June 2020 cumulative update.
You could create a temporary new farm when installing the SharePoint Server. Then install the SharePoint patch(KB28994940). After updating, run the configuration wizard to disconnect the server from the farm. Finally join this server to your farm.