If you think waiting for S1 is long, try the S3 result, or your corse start date, or contracts.
Its a long process, sometimes slow and often frustrating but HR really work hard, especially the TATC Recruitment team. They have many 1000s of applicants at Stage 1, and they do give you fair warning that you may have to wait three weeks (15 working days). Sure they are marked by computer, but dont forget that scores are not the be all and end all. dont know what else they may have to do, but do YOU really want to start with an organisation by bleating that the first department you meet 'could do better'?
Sit on your hands, try to find something ese to do becasue your result will come, and I ope its the right ne for you.