Has this BP EVER took a meal for you? have you offered live? What type of prey was offered by the pet store.
How big his your BP and can your provide details on your husbandry, cage size, temps, how you measure them, with what type of thermometer do you measure your temps, where do you take your readings, how tight are your hides, what is your humidity, how often do you handle your BP.
And please do NOT assist or force an animal that knows how to eat, if he was 6 months when you purchased him he was obviously eating.
90% of the time it is human error and husbandry related.