We did ask the builder several weeks ago to do this to prevent further water running into the subfloor area. As it has been several weeks since the request, and especially given the track record of things not being rectified in a timely manner, we decided we may as well just do it ourselves.
The last few times we have had rain there has been significantly more moisture in the ground in the vicinity of where the rainhead collector is and the batter is starting to break down and expose the footings for the brick piers under the house.
Anyway, for under $15 we have hopefully fixed this problem with this temporary downpipe. It's a sad day when we have to fix something that should have been done a long time ago.