Spam accounts are definitely annoying to say the very least. Sometimes it seems, you report them and then they come back as soon as they were removed. It’s a continuous cycle.
You can report these spam accounts by contacting Google via the Business Redressal Complaint Form here. This forum is run by volunteers known as ‘Google Product Experts.’ They are not Google employees, however they often offer great advice from their own experience working with the maps and GMB platform.
If they are unable to verify the edit, the spam account will not be taken down, unfortunately. Try again and provide them with additional information to support the issue at hand.
You can also reach out to GMB Support and get some information on where to flag the spam account. Squeaky wheel gets the oil. Keep trying until they resolve it.
The best bet is to submit the Business Redressal Complaint form and go from there. You can also try flagging spam listings via the API inside LocalViking (in the GeoGrid tool).