identified suspicious behavior in the payment activity

[#1]

Your account is suspended - We've identified suspicious behavior in the payment activity of this or your other AdWords accounts. To help prevent any unauthorized activity, we suspended your AdWords accounts.

[#2 · Accepted solution]

Hi Andras,

Your account can get suspended because it broke the rules or because it appears to be connected with another account that broke the rules.

Here are some examples:

1. You repeatedly violated adwords policies.
2. You violated our policies in a big way and put our users at risk.
3. You didn't successfully submit payment for your advertising costs.
4.Your account appears to be strongly related to an already suspended account.

Did you try filling up this form with as much details as possible so that AdWords support could investigate this at their end.
https://support.google.com/adwords/contact/pf_suspended