Depends on the type of loan, if it is a personal loan with insurance added to the loan, the loan would have to be closed and a new one taken out. You could lose out on the interest refund in this instance. If stand alone it should not be a problem unless you have already claimed on the insurance.
You may have willingly signed the forms but the crux of the misselling is whether the insurance was suitable and would it have paid out should you have needed to claim