I did have a default judgement (& a writ of control) but they finally responded to court proceedings and have applied for a set aside for which a hearing takes place in the near future (awaiting date).
I will keep the forum posted on how this develops.
Judges aren't stupid, and if you get a decent one he 'may' refuse to set it aside. It doesn't happen very often but it can.
So if you have moved to the enforcement stage are they saying not only did they not get the summons, but also the judgement?
If so you want to ask probing questions at the hearing like, have they had problems with the post, do they have a copy of the complaint to the post office, if they haven't complained, then why not. If they say they don't have problems with the post then make it clear you find it hard to believe they didn't receive not one, but two documents sent by the court, but all other mail is ok, if they say they do have problems then push as to why they haven't complained to the post office (which I'll bet they haven't). I would definitely contest the application though.