2003 MPV rear heater core
 

I have a 2003 Mazda MPV that is leaking at the rear heater core. I contacted Mazda and they told me that it was covered under the SSP 65 program, but I am out of warranty period. SSP does state unlimited mileage and is good 7 years form warranty date. Should I accept this or where can I go to fight? Any Suggestions?