AIBU to think is bloody rude?

[Shockedshell]

I dont know if I'm being unreasonable but this is annoying the hell out of me.
We are (DH & I) raising our grandson which means we currently have a few professionals involved in our lives that need to see us every six weeks. We both work and also have two of our own children still at home to care for so, like most people, we are always pretty busy - in fact life can be bloody hectic at times.
This one professional will text saying can I come and see you on such at date at such a time? I don't always see the text straight away so it could be an hour or two before I can check my calender and then respond and, 9 times out of 10, she'll text back saying sorry someone else has taken that time now!
Yesterday she text to say she could fit me in today instead of Friday like we'd arranged (she knows this is more convenient for me) but by the time I text back to say ok she'd given the appointment to somebody else
I know she's busy too but it's bloody annoying and making me feel annoyed with her which isnt good when she's meant to be supporting us in caring for our GS.
AIBU or is this bloody rude?

[Toomanypackingboxes]

Lots of people like texts as a communication method, you don't, that's fine but you need to let the worker know. I imagine she sits down with her diary and sends out a batch of texts to fit everyone in. Just tell her the texts aren't working for you and can she phone you, I can't imagine she will have a problem with this.