UC work capability assessment without forms submitted

Hi, I moved from ESA & Tax credits over to Universal Credit at the end of last year. I received my capability for work questionnaire, which was due back in March.
I hadn't finished the form & made a journal entry asking my work coach if I could get more time to fill in the form. She said she'd contact the relevant department & request this.
I then had a scheduled phone call with my work coach in May & she still hadn't heard back from them.
So it is now June, 3 months after my form was due in & I've received a letter saying my telephone assessment will be taking place this month.
I rang the assesment centre & explained they couldn't have received my forms yet. I was told the telephone assessment will still go ahead. I asked "so they don't need the forms?" She said no!
Is this correct? Should I go ahead with the phonecall??