ESA expentidture asking for evidence and receipts

Hello
A few years back I had to send my back statements in because I was over the threshold of 6k not by much, however there was no overpayments due back to the ESA
Recently I’ve been contacted again but this time they are questioning my transactions what I’m spending my money on, which I’ve provided them with evidence and receipts for the expentidture, is one not allowed to spend on certain item s? The letter has come from the ESA changes team? And there is no date to say when they need the information by, just asking what the transactions are and can I provide evidence is this because I’m flagged up on there system because my bank account went over some years ago over the 6k threshold ? I lent some money to a friend is that not allowed? But I have the evidence

Hello
Wanted to ask my capital went over 6k a few years back but
It went to tribunal (re an overpayment of 2k and it was upheld because I didn’t understand that I had to report anything because of my benefit award letters it didn’t state the threshold of 6k to 16k it just stated on mine if you have saving over 16k ESA would stop so the courts upheld it in my favour, any how I had a PPI refund last year of 2.500 and it took my bank balance over to 6,400 for a few weeks, hence the most recent letter asking for a breakdown of my expenses, so what could happen now or what’s the worst that can happen, would I be issued a penalty for a small amount over the 6k threshold