Why do I keep being told to contact Apple support when I am trying to update personal information requested by Apple ???????

Apple have flagged my account and have requested I update my personal details, this being the first time have used Apps since moving location from UK to mainland China. The rest is perfectly acceptable accept that each time I submit my details they are flagged suggesting I contact Apple support....so here I am because there is no information on the support site suggesting what I need to do next.........