I have a court judgment, and now I have received a court date as the defendant has requested the judgement to be set a side. Is this right as I have followed the procedures and time frame and the defedant has not so why do I now have to go to court??

What reason does the Defendant give for asking that the Judgment be set aside? He/she needs legal grounds, not just unhappinessd with the verdict.

The argument is usually - in my area - improper legal service.

Yes, you do have to go to court. You will present what you have done to have been awarded the judgment, and he will have to show grounds to set it aside.

If the judge denies his request you can ask that your court costs be added to the award since dragging you into court was, essentially, harassment.