Can anything be done about the prison staff losing one's personal items, such your clothing you've purchased or shoes, hot pot etc?

The inmate's only recourse is to file whatever report is within the inmate handbook. This is prison, and the staff doesnt want to be accused of anything related to lost items, etc. So be mindful in your advice to the inmate. Sometimes you have to just deal with the hardships and find away around the stuff you can't control. Having things taken, stolen, extorted from other by inmates (or guards sometimes) in prison is part of the terrain.