We are sorry to hear this happened to you. 

Here is what you need to do in such case:

  Protect your account:

Make sure that you have the safest password for your account.You may also set-up the 2-step verification method.

Also, keep your personal information a secret.

Please, keep in mind that the synchronized accounts are stored in the form of a separate encrypted code value.

Thus, there is not much we can do to help on this matter, however, we suggest you contact Apple, Google Play and Gmail Customer Services.