vgrename fails with message /dev/testvg already exists in filesystem

Issue

• Keep getting error listed below every time I try to rename the volume group..

  /dev/testvg: already exists in filesystem
  New volume group name "testvg" is invalid
  

• This volume group does not exist. If I attempt to deactivate or export the vg, I get "Volume group "testvg" not found". /dev/mapper lists a directory for this volume group.