The 48re transmission in your truck is usually a reliable unit. The weak transmission was the 47re. You might look into a DTT, or a Gorend Brothers, or a Suncoast transmission rebuilder. There are others out there but these seem to have the happiest customers. I would bet that the shop that did your work just dosen't understand the transmission. If you are in the Vancouver Wn area check with Source Automotive.
Here is a Dodge information source.
http://www.nwbombers.com