Hi TriniEK,
Yes I had a cover letter but someone told me they don't really look at it, but i believe that recruiters as i do have some HR educational background can tell alot about the person and their aims and objectives by their cover letter. All I can tell you is write a cover letter like you are selling yourself, make sure all your good traits are within the wellbeing and suited to tailor their company. Attach a pretty picture with a nice smile. My last recruiters told me its all about the smile and I love to smile
...Did you just went to the open day and didn't make it to the assessment?