I'd start by checking the exact number Google is reviewing against the website associated with the ad. Confirm the country code, digits and landing-page domain, rather than assuming that a number somewhere on the company's main site is sufficient.
Make the business number easy to find as text on the relevant website. Check the page on mobile and inspect what happens when JavaScript or a call-tracking script changes the number. An image of the number or a dynamically substituted number can make diagnosis harder.
If you use dynamic number insertion, document which number is submitted in the asset and which number different visitors actually see. Don't assume every tracking setup fails verification, but do investigate a mismatch.
Check the current phone-number verification options in Google Ads for your setup, including any website-ownership verification route offered. I'd avoid promising that one tag placement or Search Console connection fixes every case.
After correcting the issue, use the asset's available review or appeal option. Also test that the number works and reaches the business the ad describes.
Are you using your own fixed number, a tracking number, or a buyer's number? That distinction would help narrow the next check. For PPC Rebels (
ppcrebels.com) account and verification support, our contact is
Alex on Telegram.