Fighting Endo on pump brand?

Have any of you had issues with your doctor not liking your pump brand? I went on a pump for the first time this summer, I was given the choice of Tandem or Medtronic. I labored for days with a pro/con spreadsheet, calling reps, talking to friends, reading reviews. Ultimately I chose Tandem. Ever since then, my endocrinologist questions and voices her frustration with my choice. (The Tandem rep told us that this office specifically uses Medtronic, that they refer patients to Medtronic, and they don't like to work with Tandem. Is this normal? I don't know how much of this is true but I had to train my diabetes educator on Tandem because she had never been trained... even though she provided me with the choice of Tandem.)

I went in last week and my endo demanded to know why I chose Tandem because she was frustrated that she can't pull up my Dexcom charts with my insulin numbers. She wants me on the Medtronic because she has to look at two separate pieces of paper. I'm sorry, isn't it her job to work with what we have? Isn't this more information than I had before the pump? I am not the best diabetic but I am trying. Do I need to print out and provide charts to her myself? That seems ridiculous but maybe I'm not going into my appointments with the information I need to bring. Any advice on how to communicate or work better with my endo? To be honest, she's scary (which I have told her) but better than previous endos who threatened to take away my access to a CGM/pump/insulin because I wasn't controlled at the time.

Thanks!