Just wait. Relocation from the store to your home is stressful and some snakes react badly. Don’t fuss with him, handle him in anyway or disturb him for another week. Then try a whole pinkie again if it is not too big for his head. Did the pet store offer him 1/2 a pinkie? If so, how did they present it? Good to know for next week. So double and triple check all environmental parameters such as temperature and humidity, then be patient and leave him/her totally alone for at least the next 7 days.