How can I obtain a Letter for medical treatments from my doctor in Bangkok?

In BKK: I asked my expat doctor (could only talk to the staff) of over half a year if they could give me 5 - 6 appointments over the course of the next 12 months. And then just provide a Letter stating those treatments.

They answered: We're generally open to do this but have to talk to our lawyer first?!

Do you have any advice? It's a real and fair thing I regularly am at this doctor for treatment(s) and thought it would be a simple thing.

2. Alternatively: is there a doctor/ clinic that is a little bit better when it comes to treatments and a Letter about those future treatments?

Any BKK recommendations? Because I don't care where I eg get my regular testosterone blood checks done.

Thanks!!