sorry to trouble you, but ...; excuse me, but ...; pardon me, but ...
恐れ入りますが、少々お待ちください。
I'm sorry, but please wait a moment.
恐れ入りますが、こちらへどうぞ。
Excuse me, but please come this way.
恐れ入りますが、お手伝いをお願いします。
Excuse me, but could you please help?