Had a similar experience today flying MUC CDG. Checked in at one of the machines at the airport to find the only seating options offered were in the 20's ~ in TC on a Y fare.
Checked with one of the counter lizards and she confirmed that the seating I'd been offered was in Tempo and not TC. "Ah yes, the machines do that sometimes" was the explanation.....
In my case I didn't have any other problems, either at the gate ot the plane, and got a seat in the single digits. What was really annoying about it though, was that TC was only 30% full and took up around 10 rows of the aircraft.
Oh, and as per usual (at both departure and arrival) we were force fed the usual "tour des terminaux par bus". Plane scheduled from 2D ~ I believe the D stands for "dump" ~ and we were bussed to/from 2F
The words "couldn't manage a piss up in a brewery" come to mind.
S//