I'm often unsure what to say when answering the telephone when I am the customer; people usually say their name and then wait for me to say something before stating their business. I'm guessing there is a set phrase that people usually say at that point.
Usually it goes like:
- Me: はい、XXです。
- Them: XX社のXXXと申します。
- Me: お世話になってます。 ← What I'm unsure about
Is this appropriate to say as a customer? What if I've never spoken to them before? What else could I say here?