Daikin A/c

I recently installed a Daikin ac 3 in 1 system and have been having some problems with it. Recently ice would form inside and around the aircon blower even thought the ac was not turned on. Apparently the compressor would still be running even tho ac was turned off. I called up the agent and they installed a ferite coil (or somehting like that). He said that the same thing had happened to siilar ac but when they installed the ferite coil, it solved the problem. Recently my electricity bill came up to 350. Thot it quite high since I live alone and only use the ac at night when sleeping. Made me wonder if my compressor may still be running while ac is turned off. Have just begun to turn off the main ac switch to monitor my electricity charges. Have noticed however that when I turn on the main power switch next to the compressor, it makes a strange noise for about three seconds. I was wondering if that might be a sign that the compressor start to operate when the main is turned on even tho the ac blower is powered off. Has anyone got any idea whats going on?