Received an unexpected text 'Reminder' for a Capita Assessment

For context I am currently in the PIP review process, and in October I received a letter from the DWP regarding my PIP stating that my award had been extended to November 2025 and that they would contact me via letter when the review had concluded, with payment continuing as normal.

Today at 1pm I randomly received an unexpected text message stating to be from Capita "Reminding" me that apparently I have a PIP Assessment on the 20th of this month that I had not been informed of beforehand. This has taken me massively by surprise and I am completely unprepared- no letter was sent to me by either Capita or the DWP stating that there was an assessment booked so I'm a little wary.

I have always received letters in advance of any appointments or assessments, via phone or in person, so I'm questioning the validity of the message- has anyone else been text a 'Reminder' for an appointment without being informed previously?