Replying to Ski boot problems

so i got a pair of Salomon SPK 07's from my friend.and after a couple of ski seshs the left boot started to hurt the inside of my foot. like the small bone that sticks out thats under the big bone that sticks out of your ankle area.... its hard to explain but anways the boot is pushing against that bone and its causing me ALOT of pain. so i took it to a bootfitter and he said that i had flat feet (wich i already knew i had) and said i need to get some in souls that had more arch support. so i went and bought a pair of in souls. and i went to session tonight and the boot start hurting my feet again! at this point im getting pissed off about the whole delema. so i go out and buy another anckle brace to lift my arch and provide a little bit of padding for the bone. so i go and try to use the boots again and it is STILL hurting my foot. at this point i am fresh out of ideas. and i know its not because the boots are to small because I dont have this problem for my right foot. so the only idea i can think of is my friend mentioned to me to go and get my boots punched out. he said if you get them punched out it will widen the shell. so i am asking all you guys if you had this problem previously or if you can give any advice.

Would appreciate the help SOOOO much!! THANX