Or you can do what I've always done. I have a number programmed into my phone - it corresponds to whenever I last updated my contact list, so it's probably the CP number. When it asks you for your DM number, punch it in. You'll be routed to the proper agents.
I've used the same CP number through Silver, Gold, Platinum, and CP over the last several years and always end up in the right place without needing to chase a number and update my phone every year (or every 4 months as I went GLD->SLV->GLD->PLT in the last 12 months).