Rotting surrounds - again!

Question

I bought a pair of Acoustic Energy III (alledgedly high end) loudspeakers from Audio Connection in Sydney early 90s for $10K. Within a few years the enclosed woofers (3 in 1 - - tweeter/squawker/woofer) went at the surrounds. After doing a shake wuth both Audio Connection and Acoustic Energy in the UK replacement surrounds were supplied and then fitted by SpeakerWorks (LaneCove now Concord). These lasted a few years. Then back went the speakers in 2002 for another replacement set. Come 2004 a tear appears again and temp job I do to fix. Back they go again today to SpeakerWorks and the guy angrily denied (though I wasn't making claim) ever having done the job in 2002! And claims all jobs should last 15 years. Meaning I should get 60 years - not even half!!!!