Who gets attended to first

I went to Barlow world at Centurion today for service. I was first to arrive but was not attended to first. My understanding is that if you came first you get attended first but I was not attended to. I feel that I was undermined but as for why I was undermined or taken for granted I dont know. I always send my car to Barlow world en loved their service but this time I was dissapointed.