Yearly Fee

i joined planet fitness on 12-20-2014 and canceled membership on 1-31-2015.. and 1 day after i canceled planet fitness in new philadelphia ohio they took yearly fee of 30 dollars out of my bank account..i call and was told they did because it was january ..i was a member for 40 days and went there 1 time (because i didnt have the time to go) in 40 days..why would they charge me the yearly fee..dont seem right..would like my money put back in my account