Exhaust System? on 1992 Geo Tracker

I don't know a lot about cars so my level of information is just what the mechanic relayed to me.
I have replaced the "exhaust system" twice w/in the past 2 years. I was going 70 and had to pull over b/c again something was hanging from the bottom of the car. Did I get ripped off or is it common to have this type of maintenance this often?

Asked by for the 1992 Geo Tracker
The exhaust is mounted on flexible rubber mounts to allow for flexing of the engine as you accelerate and decelerate. If it were mounted rigidly (not allowed flexibility) the exhaust would crack and or the passenger compartment would experience vibration.
I suspect the exhaust was not properly mounted. Either old " exhaust hangers" broke or were missing. Look at the previous exhaust work see if you were charged for exhaust hangers or exhaust mounts.