Hello,
Andy from OSM's Data Working Group Here.
For info, Apple do credit OSM on their maps and routing in the UK, but they don't _only_ use OSM.  The last couple of issues we've had raised weren't OSM issues but issues with other data that Apple used.  Apple's advice was (verbatim):
"you can report Maps issues by following the instructions at https://support.apple.com/en-us/HT203080 under the headings 'Report an issue or add a missing place in Maps on your Mac’ or 'Report an issue or add a missing place in Maps on your iPhone, iPad, or iPod touch’ and the report will go to the relevant team that can fix the issue".
