Find and replace with variable using sed or awk

Shell Programming and Scripting
1

hi,

i have file say email.temp looks like
Bell_BB 17
Bell_MONTHLY 888
SOLO_UNBEATABLE 721

and another file r3

Bell BB,Bell_BB
Bell,Bell_MONTHLY
SOLO,SOLO_UNBEATABLE

i want email.temp files $1 say Bell_BB should be replaced by r3 Bell BB and Bell_MONTHLY by Bell of r3 and so on ..

desired output of email.temp

Bell BB 17
Bell 888
SOLO 721

i tried it with sed

rk_file=$(echo "r3")
while read all; do

   find=$(echo $all| awk -F"," '{print $2}' )
   rep=$(echo $all| awk -F"," '{print $1}' )
   echo "$find and $rep \n" 
   sed "s/$find/$rep/g" email.temp > email.file
   
  done < $rk_file

but its not giving proper result only last field is SOLO is working

let me wats wrong with sed i am doing or how can i achive this using awk ?

2 
#!/bin/bash

while read LINE
do
  OLD=$( echo $LINE | cut -d, -f2 )
  NEW=$( echo $LINE | cut -d, -f1 )
  echo "$OLD <> $NEW"
  sed -e "s/^$OLD/$NEW/" -i mail_temp
done < replacements

exit 0
#finis

[house@leonov] cat replacements
Bell BB,Bell_BB
Bell,Bell_MONTHLY
SOLO,SOLO_UNBEATABLE
[house@leonov] cat mail_temp
Bell_BB 17
Bell_MONTHLY 888
SOLO_UNBEATABLE 721
[house@leonov] bash code.bash
Bell_BB <> Bell BB
Bell_MONTHLY <> Bell
SOLO_UNBEATABLE <> SOLO
[house@leonov] cat mail_temp
Bell BB 17
Bell 888
SOLO 721
3

i am using ksh it is fialing with invalid option

sed: illegal option -- i

---------- Post updated at 05:44 AM ---------- Previous update was at 04:42 AM ----------

i achived it using

while read all; do

   find=$(echo $all| awk -F"," '{print $2}' )
   rep=$(echo $all| awk -F"," '{print $1}' )
   echo "$find and $rep \n" 
   sed -e "s/^$find/$rep/g" email.temp | grep "$rep" | grep -v "_" >> email.file
   
  done < r3