Politeness Gets in the Way

I'm still looking for a place to stay in Japan for when I move there in a month or so. A couple of days ago I called up an apartment that definitely has potential. It is close to my school, reasonably priced, and was even recommended by my school. Before calling, I wrote a quick outline (in English) of what information I wanted to tell them. My plan was to say everything about my situation up front, and then ask for suggestions on how to proceed. My main concern is being able to setup a lease before I get to Japan without having normal documentation such as the Alien Registration card.

So initially, my plan went smoothly. I called them up fine (using SkypeOut), and was able to get my message across pretty well. At this point though, the inevitable happened. Vocabulary outside of my studying scope was spoken. I apologized and explained that I was still learning Japanese, and asked the man to repeat what he had said. He immediately began speaking in very polite Japanese. This is where things get really tough. While I might be able to understand things in informal or standard-politeness "masu" form, I'm completely at a loss when it comes to even higher levels of formality. I need to learn how to say "Please speak less politely to me". The conversation continued for a bit, with me asking him questions and him trying to explain things more simply, but still the lapses into formal Japanese continued. In retrospect I think he was repeating my questions back to me to make sure he understood them, but switched them to more polite forms. After asking if he spoke English, he laughed said something to the effect of "English huh? it's been a while...." That kind of broke the ice, and eventually I was able to use my online dictionaries to discover what he was saying (even though he continued to speak in Japanese). It turns out right now is a long holiday in Japan, and the Building's Manager/Owner (still not sure which) is gone until this Monday. I guess this Sunday night I'll be making another call, hopefully I'll know how to request less polite Japanese by then.