You need to make sure you are talking about attacks and not revenges. Revenges can happen at any time, by any one, no matter what level they are or where you are. If you had attacked some one in the past they will have a revenge against you, even if you lost in the attack. Once they revenge you and win they will not be able to use that revenge again, but if you have attacked multiple times they will have multiple revenges that they can use against you.

This is true for every place except the Arena where there are no revenges.