Dragon,
I get mine filled at my local fire station. They have high pressure fill stations for their oxygen bottles. You would just need the adapter which can be purchased online. The adapter converts their oxygen tank filler thread down to the BCA bottle. Just make sure they fill it slow. If they fill fast, it gets hot and looks like it has enough pressure but then when it cools the air shrinks and could be under pressured. Not to mention a fast fill is dangerous on those bottles.
My brother fills his at Dive Utah. The guy really knows what he is doing. It costs about $10, but he replaces your o-rings, and has the lube and everything included.
DiveUtah - Ogden
1354 West Hinckley Drive
Ogden, Utah 84401
Hope this helps.