The above happened in dreams but not exactly in a dream of a telephone call. Dreams of long conversations in phone calls are rare. The audio output for a dream does not happen as often as the plain format of visual imagery in a dream.
Dreams of dead people are explained by some cultures, as visits from the deceased. A dream of audio sound messages from a deceased person, is also explained as a message from that deceased person.
Prompt – 2. Imagine that you receive a call from the other side from a person now deceased but once significant in your life (for better or worse). You now have the chance to tell them whatever you like. Alternatively you can assist this person in any unfinished business they may have had. Prompt “phone call“.