Your case must be a 100% 13. That does not mean paying 100% of everything you owe. It means paying 100% off all allowed claims. If no claim is filed, then it is as if the claim does not exist.
[I am a Virginia-licensed attorney. This communication is intended as general information and not specific legal advice, and this communication does not create an attorney-client relationship.]
Bankruptcy law allows you. as the debtor, to file a claim on behalf of a creditor that doesn't do so. I don't know enough about your circumstances to say whether or not doing this will resolve the problem you have.
If the unsecured claims were discharged in the chaper 7 they cannot come back after you because they were not in the chapter 13. Keep in mind too that the automatic stay in the 13 kept the creditors from charging interest and fees. When there is no discharge in the 13 they may come back after you later for penalties and interest that would have accrued over the time period you were in the 13.
Normally the 13 is filed right after a 7 discharge. If you got a discharge in a 7, accumulated more unsecured debt and that unsecured debt was not paid off in the 13 then yes, they can come after you.
While you must wait at least 8 years between filing two chapter 7 (11 USC § 727(a)(8)) bankruptcies (assuming you got your discharge) you need only wait two years between Chapter 13 cases (11 USC §1328(f)(2)) 4 years between a 7 and a 13 (11 USC § 1328(f)(1)) and six years between a 13 and a 7 (if the percentage to the unsecured creditors was under 70%) (11 USC § 727(a)(9)).
Please make sure you consult an attorney because you must fall under the definition of a debtor and you may have to take extra steps not normally performed in a Bankruptcy in order to make sure you are protected by the automatic stay (11 USC § 362 et seq.)
These times may also be greatly shortened if you did not get a discharge in the first case. Good Luck!
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Disclaimer: This answer does not constitute legal advice. I am admitted in the States of New York, New Jersey and Massachusetts only and make no attempt to opine on matters of law that are not relevant to those three States. This advice is based on general principles of law that may or may not relate to your specific situation. Facts and laws change and these possible changes will affect the advice provided here. Consult an attorney in your locale before you act on any of this advice. You should not rely on this advice alone and nothing in these communications creates an attorney client relationship. The opinions expressed herein are those of the author only and the fact that he has worked as an Assistant District Attorney; State Supreme Court Clerk; Special Assistant United States Attorney (Hawaii); Assistant Cornell University Counsel or Judge Advocate, United States Marine Corps should not be relied upon to assume that these statements reflect the policy of these organizations.