I applied online, had a telephone interview and got rejected before the selection event.
I would advise really researching the FMCG market, their competitors and preparing competency answers.
Before being rejected I was called up in the morning and told that the selection event I had been invited to was cancelled, which was odd because I hadn't been invited, but I was assured I had got through to the next stage and would be contacted with dates for another event. I then received an email saying I had not been invited to a selection event but I was still under consideration. I replied to this email to clarify. I then received an email saying I had been rejected. I then received another email confirming I was still under consideration. I then had to call to confirm my rejection which was fairly humiliating. The whole system is clearly not very organised. As a student you are very invested in the process of gaining internships - it really matters - to be given so much misinformation and be messed around was really quite frustrating and made the whole application process really quite upsetting.