Dyna glow rmc 55-r7 wont stay lit

Question

let it set for awhile, lite again stays lit for about 30 seconds and goes out. tried to use up all the fuel and clean the wick with a burn off, but the wick was about half lit and it took forever for the fuel to burn out.wick feels soft. this heater is only about 2 month old,it didnt seem to work right from the start, but the thing heated,and the thing in the middle stay red. if there is and answer to this problem can you tell me.i have three of these heater