弟子2人はろくに師匠の言うことを聞かずふざけ回ったって英語でなんて言うの？

• "The 2 apprentices didn't listen to their teacher well enough and just fooled around."
  "the 2 apprentices" 「弟子2人は」
  "didn't listen to ~" 「〜を聞かず」
  "their teacher" 「師匠」"what their teacher said" 「師匠の言うこと」
  "well enough" 「ろくに」
  "just fooled around" 「ふざけ回った」"just messed around" も使えます。

−The two apprentices were not listening to the master at all, instead they were romping all over the place.
「２人の弟子は全く師匠の言うことを聞かず、あちこちはね回っていた」
to romp all over the place で「そこら中・あちこちはね回る・ふざけ回る」

ーThe two apprentices didn't listen to the master the way they should have, rather they ran all over the place like fools.
「２人の弟子はろくに師匠のことを聞かず、愚か者のようにそこら中を走り回っていた」
to run all over the place like fools を使っても表現できますよ。

ご参考まで！