The Payment for Double Assurance of Mortgage and Guarantee

When there are both mortgage and guarantee in a creditor's right,the mortgagor or the guarantor could ask for paying to the debtor after they fulfilled the debt.However,the problem that whether one of them has the right to ask for paying to the other guarantors after fulfilling the debt has not been solved.The new jus rerem has only stipulated that the mortgagor and the guarantor could claim their right to the debtor.But there is no corresponding stipulation when the mortgagor or the guarantor can not be clearly paid off from the debtor.