As I understand it, factor, this was a few years ago
The mortgage was in arrears
The mortgage company started proceedings for repossession;
Surfy paid the arrears;
They weren't informed of the court hearing and the Repossession Order was granted even though the mortgage was fully paid up to date and the next payment wasn't due for a few weeks;
Surfy was evicted, house sold.
Now the mortgage company is trying to recover the difference between the amount surfy owed and the amount the mortgage company got from the sale.
In my experience the only times I have heard of anything similar happening is when the husband/wife is hiding the mail so their partner doesn't know of debts, court hearings and so on, then the partner lies and says the debts were all paid. Usually to fund a drug/gambling or other habit.
So the mortgage company has acted perfectly properly, but the partner has been deceived. I'm not suggesting this is the case here, but there are not enough facts.