Help in Possibly Awkward Situation

[NatureCulture]

Alllright. So, this was my first application season, and overall, I think I performed okay. I have a BA from a little-known small school, and I got a few interviews for top PhD programs, and received a very nice offer from a middle of the run program. I visited the school where I got an offer (let's call it School A), but I'm not confident is a strong match. The fit seems very off, and they are going through a ton of transition, which could end well, but could also end very poorly for me. I'm also still waiting to hear from School B, which I suspect is a better match, but I've heard funding has been hard to come by lately at School B. 

School A offered a strong package, and I was semi-hoping that I could leverage the offer at A with B, if B gave me a slightly less good offer. However, I still have yet to hear from B, despite my emails inquiring about the application. If I intend to politely decline A, how should I do so and WHEN? Also, I feel very embarrassed (being honest here) that I'm likely applying again next year, and I'm afraid School A will ask where I intend to go instead of accepting their offer. How do I respond to that? 

Edited April 1, 2016 by NatureCulture

[GradSchoolTruther]

You respond by telling them where you accepted. I honestly don't understand the awkwardness in rejecting an offer.

You should also decline when you know for certain you won't be attending that school.

[GradSchoolTruther]

8 minutes ago, NatureCulture said:

Sorry, perhaps my post  Was confusing. School A Is my only offer.

You're pursuing other opportunties.