Girls who can answer the phone and don't return text messages

She must have her own reasons for not returning text messages.

You don't have to think so much. Since you are willing to answer the phone, it means

She still likes talking to you.

Then you can call her often.

Don't have frequent contact with people you just met.

Appropriate chat, if familiar with the point in further contact.

The main thing is to care more about her and help her solve any problems.

Then let her know that you are a gentleman.