ALL the regulators are useless...
The ICO's website outage means that it's not possible to report yet another scam or nuisance phone cal, even if you think that reporting a spoofed or withheld number will achieve anything and you can be bothered to spend a fair bit of time so doing.
If the ICO, DCMS, Ofcom etc were any good they'd have mandated long ago that all telcos provide 1477 free of charge by default: Automatic Call Trace stores the REAL number at your local exchange for subsequent investigation and prosecution. But that would be too easy, wouldn't it?