many owners choose to go to alocal garage for servicing , providing they use genuine Honda parts your warranty is valid.
I suggest you ask around for good relaible garages run by amechanic not a service receptionist who is there for the coffee & tea .
Most car owner clubs have a 'good garage guide' try alocal centre or look at the D telegraph corres - Honest John on his website.
beware though
Cheapest does not mean the best.
Finally do not alow your oil & filter go over the 10-12k limit