A woman was left with two black eyes and smashed teeth after she was attacked during a Craig David gig.
Lisa Mathews was enjoying her night with daughter Bianca Mathews when an ugly row developed.
The pair claim another mum and daughter kept bumping into Lisa during the show at Motorpoint Arena, Nottingham.
Lisa eventually asked them politely to stop knocking into her during the performance.
But Bianca claims one of the women began screaming at Lisa and claimed she had knocked her drink over, reports Nottingham Live.
Bianca says she tried to hold the daughter's arms up to stop her attacking her mum but then the other woman started hitting Lisa.
Lisa, 52, says was unable to defend herself because of her fibromyalgia, a long-term condition that causes pain all over the body and she also suffers from ME.
Lisa suffered scratches on her eyeballs, a damaged cornea, bleeding in one of her eyes, two black eyes, dislodged teeth and bruises across her body and down her legs, her family said.
She had to go to Queen's Medical Centre and again the following morning to a specialist eye clinic.
And Lisa's family said no-one in the crowd or any member of staff came to help immediately, despite Bianca's best efforts to stop the attack. That was until mum and daughter broke free to speak to a member of staff at the end of the row where they were sat.
The pair were then taken to a room at the arena where Lisa received treatment from first aiders. She then went to Queen's Medical Centre for further checks, and then went back back again the following morning.
Bianca said: "The bruising has started to go down but it's the mental side of things now. We posted about it on Twitter, and Craig David's management got in touch with us to offer us free tickets to a show in Manchester, which is brilliant, but my mother is worried.
"We were really looking forward to the concert too. We want to get this out there as someone must have been videoing it. We don't want them to get away with it as there isn't enough evidence for police to do anything."
Bianca's sister, Dallas Mathews, said Bianca herself was also punched when she was trying to help Lisa. Dallas posted on Facebook : "My sister done all she could to keep these animals off her but it was all too quick."
The violence erupted during Craig David's set on Thursday, April 7. He was in the city for his Hold That Thought tour, the show having been rearranged from the previous year.
Bianca had bought the pair tickets at Christmas and travelled to Nottingham on the day to enjoy the concert and planned to stay overnight in a Premier Inn. Bianca lives in Leicester and Lisa in Cambridgeshire.
Detectives launched an investigation but said the case had been dropped due to insufficient evidence. Officials from the arena, in Bolero Square, have apologised and said security staff intervened once they became aware of the situation.
Police Constable Matthew West, of Nottinghamshire Police, said: "We recognise this woman has been through an unpleasant ordeal and have conducted a full and thorough investigation into this alleged assault.
"After reviewing all available CCTV footage of the incident and carrying out other lines of enquiry we concluded that there was insufficient evidence to support a successful prosecution.
"The victim has been made aware of the outcome of our investigation and has been advised that it can be re-opened should any further evidence come to light."
A spokesperson for the Motorpoint Arena said: "We're extremely sorry that Lisa suffered this assault and sustained injuries. We wish her a speedy recovery.
"Once our security team became aware of the incident, they quickly intervened to stop the assault and detained the offender, assisting the victim to the medical room where she was looked after by paramedics.
"As always, we will support any police investigation into the incident with the information we can provide.
"As a venue, we have everyone's safety at the forefront of everything we do. Our security and stewarding operation is extensive, involving detailed planning and preparation for each specific event.
"Our dedicated security team complete regular training to ensure we uphold the highest of standards in order to look after the hundreds of thousands of people that visit our venue every year.
"Unfortunately, there are occasions where customers let themselves and everyone else down with unacceptable behaviour.
"When this occurs, our teams respond as quickly as they are able to with the challenges that a dark, busy Arena environment full of over 8,000 people presents, to prevent further incidents and to assist anyone adversely affected by others’ actions."
