Four levels, ten recordings each. The audio never gets slower — what changes is how much is repeated back to you and how far the wording on the page sits from the words you hear.
You hear: “So that's the Tuesday group — sorry, no, the Tuesday one is full now. It'll have to be Thursday.”
The form says: Class day: → Thursday
Two days are spoken and only one is the answer. The first is withdrawn, so the second stands. Sorry, no is the signal here — but at B2 it softens to actually, and at C1 it disappears completely: “The Tuesday group is full. It'll have to be Thursday.” does exactly the same job with no apology at all. That is the whole ladder in one sentence: the trap does not change, the warning does.
Carry into the mock: when a speaker gives a value twice, write the second one — then check the word limit before you move on.