It is essential that you respond to this summons. If you have moved far away and it is no longer possible for you to appear in court in the county in which you used to live, then I would recommend you either talk to an attorney or contact the courts to find out whether you can have been the case moved to another locale. Of course, if you are able to settle and resolve this debt before it goes to court that would be ideal.
You may want to read our pages that talk about what to do if you are being sued by a debt collector.
Whatever you do, do not fail to appear in court when you are required to do so or the debt collector will automatically get a judgment against you and that opens up additional avenues for them to collect.