Which office deals with that?

 if a person went to social assistance while their undertaking is still in effect,then they have defaulted and will have to reimburse the money that was paid.if that money has been repaid,then you need to contact the office that handled the social assistance payments and they will provide  you with the proof that they have been reimbursed. once you have that proof,then there will ne problem.if you send in your application without getting that proof,CIC also do their own checking and will ask if you are in default or if it has been repaid,you can get the letter and include it with your application if it makes you feel better,but not recommended.hope this helps,though i am not sure if that was your question.