KING KONG 260 FPV Plug and Play Racing Drone

Hi, I purchased the above item in August for my Grandson and it's Ok, a great little drone to learn FPV with. But have replaced one ESC in September from you only to have another burn out today after just one flight. I am using Turnigy 3S 2200mAh batteries and the Props supplied, so am not over exerting the ESC. As you can understand he is visibly upset that with each failure he is then unable to fly for several days while the replacement is in transit and then has to wait for me to solder them in. Is it possible for you to send at least one or maybe two ESc's (KINGKONG 12a Opto BL Heli 2-4s) to assist us plus why are they burning out or is it just one of those things.

regards, Pete