I alo had a hard drive seagate 1 tb crashing not within apples eries numberts but just a FEW MONTS AFTER GUARANTEE

My son has an Imac 27" from may 2011 with a seagate 1000gbytes (had) hard drive with unrepairable faults. Have just changen hard drive. Read today(http://support.apple.com/kb/HT1750 apple extended replacement of drives). When I check my serial nr. not for me. Obviusly Apples Seagate hard drives have issues extending beyond theyr given serial numers. My sons crashed under normal usage. Affected hd serial nr 5vp85989.Anybody else with harddisk crashes . Shoul we go together and complain. I have time 😉