Friend has recieved a court summons under section111A of the social security act what is this?

she was interviewed under caution last year with regards to over payment of housing benefit (�4000) in total, she admitted that she had not told them of changes in her circumstances and was told by the interviewer that they would take everything into concideration and they would let her know what would happen within 14 days, she then got a letter saying she had to repay the over payment which she has been doing now for over 8 months, but suddenly out of the blue today she has been sent a court summons under the above act all we can think is that it is connected with the HB overpayment, she has 2 small children and is pregnant with her 3rd and i am just trying to find out what is likly to happen in court and why if she is paying the money back does she now have to go to court? can anyone please help with this. Thanks