Phone call from.DWP.after submitting tribunal application

I applied for higher rate mobility after a PIP review. It was refused so I applied to tribunal.
The DWP called today with no prior notification. Asked questions that they already have answers to . Its all on the forms they have.
They asked me how many times a week I go out, which I think is irrelevant. Also asked me why I have changed to an automatic car, which I already explained in detail at my PIP review .The person also asked about aids and adaptations, which they also have full information about from my review form. I object to being asked how many times a week I go out. That is a personal choice and I don't see how it's relevant