For accounts suspended for suspicious payment
Free tip (though it is a HAF) : When a Google Ads account gets suspended, it is at that point of time itself when their algorithms decide whether to reactivate or not, IF INCASE (subject to) an appeal gets to be submitted.
Appeal each and every suspended Google Ads account be filling and submitting the Google Ads account suspension appeal form.
In the last box of the form, write stuff like : You have not violated Google Ads policies, your campaign is compliant with Google Ads policies, the Google Ads account has been suspended by mistake in error, you will use Google Ads in a manner that is compliant with Google Ads policies, etc.
Avoid copy/pasting the exact same story in all appeals. Make few changes and make it unique or appear unique each time.
And Google Ads can suspend an account even for no reason.
NO MATTER what the suspension reason(s) show as, appeal each and every suspended Google Ads account. Remember, that in 99% of account suspensions showing as suspended due to payment, in reality it has NOTHING to do with card, vcc, billing, etc.