Phrase(s): I didn’t (quite) catch that (last) remark. [and] I didn’t get that.; I didn’t hear you.
I didn’t hear what you said, so would you please repeat it. • John: What did you say? I didn’t quite catch that last remark. Jane: I said it’s really a hot day. • Bill: Have a nice time, if you can. Sally: I didn’t get that. Bill: Have a nice time! Enjoy!
McGrawhill's American Idioms And Phrasal Verbs