Hello!
I'd say Revell Germany has a great customer service, especially when it comes to parts - because they send you parts for free, they don't even charge any shipping, and they actually need only a polite request - no need to prove you're a legitimate buyer or any stuff like that.
One problem though - as one nice lady from Revell once told me - they get swamped with parts requests after Christmas and it takes them usually until April to process all of those. From April on it only takes about two or three weeks to get the requested parts.
Hope it helps, have a nice day
Paweł