repeated calls over the last two week no message left.

It's Convergent, formerly ER Solutions, a third party debt collector.  They have a reputation for attempting to collect debt that is past the statute of limitations.  Here is the Consumer Affairs site with complaints about this company.  Read through them and note how many say the debt was old or that after talking to the original agency, found out they had no debt.
https://www.consumeraffairs.com/debt/ersolutions.html

Follow the advice of the FTC regarding debt collection and identifying phantom debt.
https://www.consumer.ftc.gov/articles/0149-debt-collection
https://www.consumer.ftc.gov/blog/lesson-phantom-debt-collection
https://www.consumer.ftc.gov/articles/0258-fake-debt-collectors
http://money.cnn.com/2015/11/11/pf/zombie-debt-collection/