Mr Roy
I am concerned that you say your wife was worse off after transfer to ESA, she should not have received any less than she was receiving under IB.
You should not need to contact the DWP, in fact, they have rejected calls from other members about this, they intend to contact all claimants who they believe are affected.
To be eligible for the back payment your wife is going to have to show that she is entitled to Income Related in addition to the Contribution Based ESA she currently receives. ESA(IR) is dependant on your household income, your savings and assets, and any hours that your partner works. See
Asset and savings rule for ESA(IR) 24 hour work rule for ESA(IR) Gordon