The N97 has its own dedicated customer service number here in the UK.
I'm sure there'll be one for the N900 as well.

In terms of repair, I don't think Nokia is doing a great job.
Some people have to wait for a month for spare parts, meaning no phone for a month, even worse when paying for a contract.
Nokia did compensate with 5 free download from Nokia Music Store for several people who are in this situation but nowhere near enough.