Bad service

I replaced my car battery just last year April two months later took my car for a service and again later in the year for a service and again at the beginning of this year. Now this month I'm told I need to replace my battery again hardly 1yr 5months.I enquired with one of the places that replace batteries they laughed and said a battery life is 3-5 unless the battery was just recharged and the old battery was replaced again. I paid for a new battery to be installed. Also that what did they check during both services because checking the battery is part of the service. I am not paying for a new battery this is so unfair and I feel you are just making money out of me. Yes I do understand that warrenty of the battery is a year but I brought the car twice for a service and no one saw that. This is the worst service ever that I have received at ECM since my first car in 2011. I am so dissatisfied and disappointed