I had a similar situation: a person I do not see, but a telephone contact.
We have some similar interests, but the conversations started to be her talking and the time spent got to be excessive. I informed her that I needed to limit the time on the phone, and she was offended and defensive and she wanted to know why? This happened over a period of time...so.....I told her that we can email. Maybe this will work for us for now. We will see.