Student or Learner
I am reach your mobile phone and Eric. Would you please return your call to Ms. xxx, she is looking for you urgently.
From what I can understand you are trying to reach Eric or a 3rd party on their mobile. If this is not correct please advise what you are trying to say.
Sorry, I have been unable to contact Eric or yourself, on your mobile. Please ( or your could say...return the call to Ms xx urgently ) contact Ms xxxx urgently.