You need to put the variable inside single quotes when you print it. You think you did this but you didn't:

print "Buffer is : "${REC_BUF[CNF_REC_CNT]}""

First quoted string:"Buffer is : "
Unquoted string: ${REC_BUF[CNF_REC_CNT]}
Second quoted string: ""

Maybe you wanted:
print "Buffer is : \"${REC_BUF[CNF_REC_CNT]}\""
which is now a single quoted string.