The provisions of Sections 29-3-680 to 29-3-760, which are intended to affect the remedy of foreclosure, shall apply to the foreclosure of all real estate mortgages now existing and those hereafter executed but, if held invalid by a court of competent jurisdiction as to the former, they shall nevertheless be fully applicable to the latter; but unless the petition required by Section 29-3-680 be filed within the time prescribed, no deficiency judgment shall be affected hereby.
S.C. Code § 29-3-770