I can only guess at what was intended, but possibly it was meant to read “Hardly had I put down the receiver than there was a knock at the door.” (i.e. second “down” deleted).
“Let’s try to get home quickly before the rain really sets in.” (“sets in” = becomes steady and persistent)
“I wasn’t told” is a passive form that would have to be followed by something like “I wasn’t told about the meeting”, or “I wasn’t told the truth by my boss”, or whatever. “I wasn’t told you the truth” is ungrammatical.
“I did not tell you the truth” is correct English, but that is not an option. The correct answer is “I haven’t been telling you the truth.”