hwacheon, reading your post reminds and reinforces the need for mystery shopping.
Schedulers may not be the best at responding to emails in a timely manner. However, EPMS publishes their phone number, and almost always answers the phone. They have talked me through a few sticky shops.
txshop, I shop targets and anyones. Targets are a bit trickier to deal with on my end as they relate to my schedule. When EPMS sees your phone attempts, and you communicate with them that the target has not been reached, they will extend your due date.
For the phone portion, don't lead the agent. You will ask almost no questions. You will initially express interest in an apartment. They should take it from there. They should ask what size apartment you want, what date you want to move in, what your budget is (I answer that by asking what the rent is and after hearing that amount, I state it is within my budget), how you heard about them, if you have pets, how many people will be living there, if you have any special needs (you might answer that you would prefer ground floor, or third floor; or you may indicate you need space for a home office). The leasing professional should invite you to the community, and may ask for an appointment. Just have your scenario planned. Don't offer too much info. I often have pregnant pauses in my phone calls, giving the agent every opportunity to get it in gear.
Make sure you get the agent's name. You will be able to listen to your call, and then report the phone portion.