pcplod

Three times in the past three months when trying to start my 2016 Legacy with 14000 miles, the battery appears to be absolutely dead. Selling dealer can find nothing wrong and in desperation finally changed the battery on the second visit but, lo and behold, one month later, same problem! Car is always garaged, is well maintained and someone suggested that perhaps I don't use the vehicle often enough and the problem would be eliminated if I drove the car everyday! Not acceptable! I am retired from an almost forty year career in the sales end of the automobile industry and I have never heard of anything so ridiculous. Although not started everyday, vehicle is used three to four times per week accumulating between ten and eighty miles per use. Any suggestions before I trade this car in which will occur within the next week. Thank you