I've said it before, I'll say it again:
Don't call a literary agency.
Unless you are invited to call, or you are represented by the agency, stay off the phone.
In case the corollary isn't clear, let me say this next thing plainly:
Don't call an editor either.
And really don't call pretending to call for your (or any) agent.
The only thing this does is give me fresh material with which to torment Moonrat next week.