Describe a time when you gave excellent customer service? All your classic customer service questions: what is good customer service to you? What are your strengths and weaknesses? What role do you play in a team? Etc.
I wouldn't recommend even entertaining their recruitment procedure but if you do ... the key is to ooze confidence. In the first group interview it is always the people who are willing to give their 2 minute presentations first and are outspoken that make it to the job or a further interview.