IELTS - British Council

My son has just written the exam to teach in Australia . He received between 8.5 and 9 scores for all his exams except the written one which they gave him a 6.5 out of 7 . Please explain to me how a person who passes everything else with flying colours in English and fails the the written exam by .5 . Something strange going on here . He then asked for remark and they could not have done as he had a reply within 5 mins that his mark stays the same . This is a person who received distinction in his teaching degree for english .What a farce and complete money making bunch of nitwits. He has to now pay R3500 to rewrite it and another R5000 to fly to Durban to do it .