The victim, aged in his 30s, is said to have been assaulted by a group of people while he walked in Skinner Street between 9pm and 9.20pm on Friday 16 April 2021.
The man sustained injuries to his face and arm, which were treated at a local hospital. He is also said to have been racially abused in addition to being punched and struck with a golf club.
Two of the suspects are male, with the third female. They are all described as being young, possibly teenagers, and were dressed in dark clothing.
Officers have carried out numerous enquiries, including speaking with potential witnesses and seeking to obtain CCTV.
Anyone with information, or privately held video recorded in the area at the time of the incident, is asked to call Kent Police on 01634 792209, quoting reference 46/63535/21.
You can also contact the independent charity Crimestoppers in Kent anonymously on 0800 555 111 or complete the online form at www.crimestoppers-uk.org