I have the Sensatracs on the rear of my '88 Acura Integra, and it is a mistake I will probably decide to live with. These are absolutely the worst design of shock absorber anyone could dream up.
The idea is that for small displacements, the suspension is not working hard, so the damping can be weak - allowing a good ride. When motions become larger, stiffer damping occurs, because the suspension is working harder. The system is 'position' sensitive, accomplished with grooves in the cylinder wall.
Unfortunately, real-life is different. Variable valving needs to be 'velocity' sensitive to compensate for increased suspension activity, as Bilstein and others do. The net effect of the Sensatracs is that on large bumps, the weak center valving allows a rapid acceleration of motion followed by a sudden stoppage - it can launch you right out of your seat (or your lunch out of...)!
Whether the shocks they installed were the correct model for your application or not, I recommend you drive carefully back and have them re-install the originals until you can make it to a shop that can handle the oem brands.