Yes, the residence office are jackasses who don't pay any attention to what's written on your form.
Max Rayne is certainly one of the cheaper options available, so be happy. It may be that your maximum weekly price wasn't high enough to slap you in any of the residences closer to UCL. You do get the 'free bendy bus' though (also known as "that's the second ****ing number 29 that's driven past without stopping 'cause it's full, screw it, I'm walking.") The walk can take as little as 30 mins if you walk briskly, 40-45 if you walk at a gentler pace. I also don't reccommend trying to walk in with just the UCL map to assist you on your first day with very little time to spare... I ended up walking in the wrong direction, and missed one of my 'introductory lectures'.
I'd definitely reccommend trying to get hold of a bike; the ride is quick and fairly pleasant despite the smog, and most of the time you will be whizzing past buses.
Enjoy Max Rayne whatever happens. It is quite a nice place, even if you might think that the kitchen and bathroom facilities are dire at first - you'll get used to them, they're not that bad. Certainly better than some other places; for example you get a decent sized, lockable cupboard in the kitchen for all your stuff, there are two cookers in most kitchens - and they're refurbishing it all floor by floor, so you might get lucky and get a snazzy newly-done kitchen.