Dismissed Chapter 13

I claimed Chapter 13 in Sept 2008. In April 2009 I lost my job. I was told by my lawyer that I had a 6 mo window of time where I could make no payments and I would still be able to continue my chapter 13. I anticipated finding a job within that 6 months but did not. I am employed full time now and recently one of the collection agencies have tried to contact me. I have not responded to them (they made a second call today) because I'm not sure what to do. I did not file chapter 7 at the time of the dismissal because my lawyer wanted additional money that I could not afford to pay because I was unemployed. What are my repurrcusions for not responding to the collection agency? I mean my credit is already shot.

Thank you,
Dee