Hello there, I am a business English teacher and I have a great role play to practice telephone skills. In this one it's Christmas: one student works for Amazon, sending out packages and the other works for DHL who will deliver the packages. Sit your two students back to back and the Amazon student must read the information from their sheet, while the DHL student copies in down correctly.
Full instructions here: http://www.bilinguanation.com/tefl-roleplay-the-telephone-roleplay/
Let me know if you have any questions. :)