When you say a 360, do you mean it did a roll on its own? What you are describing sounds like a radio problem. It could be that whatever caused the glitch in your aileron servo also caused your throttle servo to go all the way closed too. For future reference, when something doesn't look 100% right on your plane, don't fly it. When you have a problem and manage to save it, don't fly it again until you figure it out.

You say the plane is 4 years old. Are the batteries that old too? If so, they could be bad. NiCd's can last a long time if they are cycled properly and stored without temperature extremes, but just sitting there discharged will kill them pretty soon. So the batteries and switch would be the first place I would look. How old is your radio? If you bought it used 4 years ago, it may have some corrosion and be at the end of its service life.