Victoria Police say they're investigating why a statement wasn't taken immediately following the vicious bashing of a Western Sydney couple in Melbourne's CBD earlier this month.

Lisa and Mark Hession, from Erskine Park, were set upon by a group of African and Islander youths on the corner of Little Bourke Street and Swanston Street in the early hours of May 5.

The couple was in Melbourne to celebrate Mark's birthday.

Lisa and Mark Hession were visiting Melbourne when they were set upon by a group of youths. (9news)

Lisa said she was bashed by four women. (9news)

"There were four females attacking me," Lisa told A Current Affair in an emotion-charged interview.

"They ripped my hair and my face has just gone down and I felt really hard punches."

Mark tried to stop the unprovoked assault, but he was overpowered.

Among Lisa's injuries was a fractured eye socket, which could lead to a loss of eyesight. (9news)

Lisa suffered serious bruising to her body and lips, but the most concerning injury was a fractured eye socket - which could lead the mother of four to lose sight in her left eye.

To add insult to injury, the couple claims the Victoria Police officers on the scene didn't take a statement or any photos of their injuries.

Melbourne's alleged gang violence problem has been making headlines. (9news)

After repeatedly contacting the police station, Lisa was told three weeks later that the incident had never even been officially recorded in the system.

"They've not done their job," Lisa said.

In a statement, Victoria Police says its looking into why a statement was not taken immediately after the attack, and will contact Lisa.