Yes, I have had the wrong item sent but the part number and description were correct. That happened twice with the same item on consecutive orders and UK DS noted that and said that if it happened again the picker concerned would be spoken with.
I have also had the right item with the right part number on the order, but the description on the order was wrong - presumably an error inputting data when setting up the database.
I've sometimes had more of a part sent than I ordered, usually very small parts where I guess the picker, rather than counting out, say 25, just grabs a big handful; probably getting towards the end of the day.
Lastly, I have had items I didn't order sent and been told to keep them.
Having said that, compared with the hundreds (thousands?) of items I've ordered over the past 20 years, the number of errors is small.
Steck framework and walls seems to be a bit of a blurred area at times as to what you get. At one time, I'm sure gable ends had to be ordered as separate parts, (framework, wall, window) but on my last order the framework number covered everything.