How to generate permission denied error in CIFS mount point

There was a requirement to generate permission denied error in CIFS mount point when ever user was accessing the mount point. in out case /BRKTS

in /etc/fstab following lines gives full access
//setappprodn98/VAL         /BRKTS          cifs  username=sell_user,domain=na,password=123hjsdT,iocharset=utf8,sec=ntlm  0  0


in /etc/fstab following lines gives permission denied access
//setappprodn98/VAL         /BRKTS          cifs  credentials=/root/.cifsauth/intg_val_auth,uid=sell_user,gid=selluser_fileshare_val,iocharset=utf8,file_mode=0770,dir_mode=0770  0  0