Same phone number with multiple extentions always get registred in the call log with one single user

LG L90 with Lollipop 5.0.2. I'm using the default factory Dialer, Call Log, Contacts app (all those options are running under the same app).

I created multiple users with the same phone number but then I add a coma (,) and then for each user use a different extension.

For example:

John Doe 1 555 555-5555, 2000
Mary Jane 1 555 555-5555, 2001
Jane Roe 1 555 555-5555, 2002

The problem is that when I receive a call from the office the call always get registered with the first user that I create with the number. For example I made a call to Jane Roe but that call get registered as John Doe or I receive a call from Mary Jane but the name on display is John Doe. With that I can not know who call me from the office. If I try to re-dial that last number it is always John Doe that shows up and then the dialer dials 1 555 555-5555, 2000 instead of 1 555 555-5555, 2001. If I delete John Doe then Mary Jane (the second user that was created), is the account that get always registered in the call log. How can I fix that?

Thanks!