Please help me! Equidebt, defaulting

A question about : Please help me! Equidebt, defaulting

After sending a letter, on the 24th January, to Equidebt saying the loan they are chasing is statute barred and we don't acknowledge it, we have a letter saying you have defaulted on your credit agreement, this can no longer be seen as an oversight, blah blah blah pay us now.

I don't think they have received the letter, it was posted recorded delivery but Royal Mail have no idea where it is. I'm worried that they have received it and ignored what the letter said.

Do I just send the letter again?
And what does defaulted mean, and what do I do in response to that? Should I ignore it until I know they have received my letter?

Best answers:

• Follow up letter here:
  https://forums.moneysavingexpert.com/...47&postcount=4
  What they are saying about having "defaulted" is just the bleeding obvious. Muppets.
  Doesn't stop it being statute barred though, so it's not at all relevant.