I have questions for the ESA

Good day On 21th March 2015 I received letter informing me that awarded ESA, also writes *We will pay your allowance into the above account from 18 March 2015*. But to date has not paid money. I was awarded PIP
from March 2014.
1o have to i wait some days;
2o i will get arrears money from the day the application? or from awarded esa? was wondering if you could help.


Thanks very much for your time and help.