service agents for most stringing machines (in uK) inc Neos/Prince are Apollo Leisure (01202 821000) who are based in Bournemouth.
They will travel to do servicing but yo'll have to pay travel mileage. Best would be to send it to them. However they're not open until 2nd January.
Highly recommend these guys. Have worked with them for nearly 25 years; they also run the Wimby stringing service; and lead technician is a highly knowledgable and respected guy within this field.
Head IG Prestige MP; Wimbledon stringing team since '04 - Head Wimbledon stringer '14; Babolat stringing team '10-'14. Twitter - @therqtstringer