PIP decision letter arrived but ive had no text or back payment.

I've received my letter from PIP and ive been awarded it but ive not received a text saying that ive got it. I had to call up and ammend my bank details as they were wrong and this was on the 6th. How soon do you think it would take to recieved a back payment from this? Will it be next week or longer due to the ammendments on my bank details?