Elementary, my dear dummie

The same person continually insists upon calling me for support. She refuses to email for whatever reason despite the fact that I have explained upon dozens of occasions that if I'm busy on the phone, she can email me with what she wants.

Today while I'm on the phone the woman calls. I send her an email that says, "I'm on a call, what do you need?"
Her response is to bring a phone down to me and she starts talking, I point to my phone, she walks away.

Thirty seconds later the call waiting chimes, it's her. I email a second time. "I'm on a call, what do you want with this phone?"

The call waiting hits. This is the THIRD TIME she's been too stubborn/stupid to figure out I'm not going to answer.

Finally she responds with her request. Along with a demand for the timeframe of when it will be done.

It was a simple request so I fixed it and emailed her that I was still on the call, and she could come get it any time.

Fourth call...