Public Service Centre director, Supranee Chantraratanavong, said yesterday the centre had never rejected a complaint and it fully welcomes anyone who comes into the centre.
The agency can receive more than 200 complaints a day, she added.
She also brushed aside reports the centre will be shut down, saying it is a misunderstanding.
Ms Supranee said the centre, which is currently at Government House, will be moved to the first floor of the Office of the Civil Service Commission, opposite Government House.
She said complaints are normally separated into categories of social and welfare, grievances against state officials, economy, politics and administration, laws, and natural resources and environment.
The five most common grievances are people causing a disturbance, narcotics, loan sharks, gambling, and electricity problems, she added.
The National Council for Peace and Order (NCPO) set up the centre after the May 22 coup to let people voice complaints on any issue, to help build support for the reforms it is undertaking.
On June 26, the Office of the Permanent Secretary in the Prime Minister's Office launched a 1111 hotline, which has 100 officials on hand to receive complaints.
People can lodge complaints through three other channels by visiting the website, www.1111.go.th, using the 1111 PO Box, or turning up in person at the Public Service Centre.
Ms Supranee said that overall more than 45,000 complaints had been lodged since May 22.
Sathit Suthiserm, who works as a legal officer at the centre, said at least 70-80 people turn up to the centre every day, but only six officers are on duty.
Many people have been to the centre a few times to complain about the same problem.
Repeat visits were caused partly by the change in administration and the change of agency chiefs who help deal with certain problems.
Complainants should expect a short delay.
The centre merely forwards complaints to the NCPO and state agencies responsible for further attention.