This isn't a web related question, but it's businessey.

So the other half of my work is photography (yes, Sagewing, still doing both...), and I've had an ongoing job (through an advertising agency) doing portraits of a particular client's employees of the month.

This had been going very well, and they've consistently called me for several months until one day, about three months ago, when the date they booked for portraits clashed with my work for another good, regular client. I'd given favour to the other client, frankly because they pay more, and the agency used another photographer that day.

Why did the dates clash? I'm not sure; I've told the agency a few times before that my Mondays are committed to another project, and that month they chose to book a Monday anyway. Hence the clash, and hence me opting for the other regular client.

Here's the problem. The agency hasn't called me back since.

I imagine this means that the new photographer worked out and they've been using him for the past three months.

I'd like to be greedy and get back in though. So my question is, what is a tactful, unembarrassing way to re-establish that job with the agency. I'm reasonably close to the account executive, and actually pretty friendly with quite a lot of people in there; So getting in to speak to someone wouldn't be a problem at all. I just am not sure what to say.

Obviously the bigger picture is that I need to grow my work bigger than a one-man show if I want to greedily chase a bunch of jobs at once, because I can't be everywhere at the same time. I have a rough plan to do that over the next five years. But as of right now, I consider that agency and that job a warm prospect, and I'd like to do something before too much time passes and they get used to the second guy.

Thoughts? Criticisms? Suggestions?

Thanks, everyone!