A3 wing mirror glass help
 

Dear Sir
I have an A3 (8V) 2013 1.6 diesel for about 2 weeks now. I just noticed yesterday the driver side wing mirror glass has slipped down inside the housing so it is not centered anymore. The mirrors are electric folding and heated. The mirrors have not been knocked as far as I am aware. Can you please advise the possible cause and as to how to remedy this? Do I need to take it to a garage or will I be able to fix it myself?
Many thanks,
Anita