I see this all the time around here. I just had to re-do a stump grinding job last week, after the previous contractor left about 30% of the stump and roots above ground, buried under all the wood chips they left behind. In fact, this happens around here at least 50% of the time that people pay to have a stump removed. They dont actually finish the job. Then they leave all that useless debris behind for the homeowner to figure out what to do with it. But the biggest screw-up I had to fix happened a year ago, when I was hired to figure out why a drain was not working. A customer of mine had been at home on a day it was raining, when this guy knocked on is door and advertised his work. He then noticed that water was pooling where the driveway met the garage, and was puddling in the garage. So this guy basically pushed my client into hiring him to do dig a trench through a corner of the driveway, drop in a drain, and run a pipe under the drive and into the yard, then over to the small hill and out. Unfortunately, my client didnt pay attention to the work, and the guy ripped him off and screwed up the job royally. First of all, the guy would stop by about 2 days a week to work, then disappear. Every time he was there, he asked for yet another check for several hundred dollars, which totaled $2300. He installed the drain, then didnt dig the trench anywhere near deep enough, and he didnt install a corner connector from the drain to the pipe, used a 2" drain pipe, when he was supposed to use a 4" pipe to connect to the drain, then he didnt connect the 2" pipe to the corrugated 4" pipe leading out into the yard, where the trench was too shallow. But then, he simply poured asphalt into the driveway trench, over the undersized, unconnected pipes, which werent deep enough by 6" anyway! Then, he buried the corrugated plastic pipe in the yard, with no drain slots in it, with no sleeve/sock over it, and buried it into pure clay and backfilled with clay, with no stone! It ran to nowhere! What was worse at first, was that the asphalt didnt set and harden after 6 months, which ended up being a godsend, because I was able to dig it all back out with a shovel before using a jackhammer to bust through and deepen the trench, before connecting the correct 4" pipes. Then I re-dug the yard trench and deepened it, before using this new all-in-one drain pipe system that is wrapped with a sock and surrounded with foam like pieces to allow the water to drain through The whole drain was only about 25' long, and only went under about 9' of driveway corner. I encouraged the client to call the guy and get his money back, and I even called the guy myself, but his son(who helped him with the job) claimed he was sick and had moved to Florida(BS)...... So my client swallowed the loss, as most people probably do. I re-did the entire job for $600, even though the other guy charged $2300! It only took me about 8 hours, and I had to rent the jackhammer and buy all new piping. I took pictures of the old job as I dug it up for posterity. Whats the worst you've seen?