My VHP had its battery change by the previous owner and this has messed up the perpetual calendar which can only be reset by Longines. I contacted them through their website for advice, two days later a pre-paid envelope arrived and today the watch was delivered back to me after two weeks by courier all sorted and in a nice travel case - with no charge for the post and work done.
The watch is four years old so well outside of any gurantee period and again Longines surpasses others with its attitude to customer service; its not the first time that I have experienced something along these lines from them.
Keith