Does anyone know the up to date rules on vat exemption on children's clothes?

I bought an age 9/10 school coat, a pair of age 9 jeans and an age 11 top from Marks and Spencer and paid vat. According the The Times (Aug 08) all children's clothes designed for age 14 and under should be excempt but M&S have told me that only age 6 and under is excempt. Does anybody know the correct ruling? Many thanks.