Hi Penny51
Yes, people can still be sent an assessment without the form being completed - they have to work with something.
Assuming that you want to claim PIP - you could ask them for a different time or even a different type of assessment. Obviously a paper-based assessment won't work, if they don't have information on you. You could ask for a telephone assessment if you think that would be easier. (I know none of this is easy). You can ask for a change of date and time, but you can do this only once. Whatever they offer you the second time you would have to take.
BIS
Nothing on this board constitutes legal advice - always consult a professional about specific problems