When call waiting is turned on, you can answer a new call without ending your ongoing call. If you're a on a pay as you go price plan, you can hear the new call but you can't answer it without ending the ongoing call. To use call waiting, you need to turn on call waiting.
When you have an ongoing call, a new call is signalled by a sound. Press ANSWER to answer the new call.
Press the call on hold to activate it.
Activate the call you want to end and press END CALL.
Press END CALL to end the other call.