Benefit And error compliance letter

2 week ago received this letter, I phoned the woman up she said nothing to worry about just checking your getting right ESA benefits which made me relax a slight bit more but not much, I claim ESA for my wife, when my wife and I got there the lady said she was glad my wife came with me, as we have information my wife has over 9000 in savings, which stunned us as we only just manage month to month, to cut the story short my wife had to produce 2 years back dated bank statements which we done today showing no sutch money.
The case has been closed now, she also indicated there info had come from a phone call to another department, the whole experience wasvery worrying to say the least, now we can get on with our lives, ps during my 2 week wait I got my PIP results enhanced mobility, standard care, thanks to this site and all the info, I am now going to request mandatory recon. Good luck all