What is the expected life-span of a Rega cartridge

What is the expected life-span of a Rega cartridge? More specifically the Exact.
That depends on how clean you keep your vinyl and your stylus tip. Don't worry about it my friend. Just keep things clean, enjoy your music and occasionally inspect your stylus tip under a 20x magnifying lens. When excessive wear appears, replace the stylus if possible or replace your cartridge. Keep it simple. Don't fret things like this.
The reason I ask is because I purchased a used table (supposedly between 2-4 months old) and I was picking up distortion in the upper octaves. When I brought it back to the dealer they heard this as well. However, the salesperson told me that it was the cartridge, and that I needed to buy a new one. Once I picked my jaw up off the floor, he began telling me that cartrides have a hae a life span of 2 years or so and that they personally reccomend that their customers replace them every two years. Once I asked them why a (now 6 month old cartridege) would start sounding bad...the dealer began cahnging the age of the table on me yet again, now saying it was over a year-and-a-half old.
So I guess my real question may be, is this bunk or am I just going to be left hanging?
If the table is indeed a year and a half old, and it has been played alot, the cartridge may be played out.

Personally, if I had any doubt about it, then I would get a new cartridge. My record collection is worth alot more to me than an old second hand cartridge. A worn out stylus can do damage to the records.
Change dealers then figure out if you need a new cartridge.Get rid of that dealer first though.
So what do you guys think I should do about this dealer situation? They have changed the age of the table three times on me, and now I am left to buy a new cartridge it sounds like. So far, I have still been nice to them but I am about to explode on the inside. I haven't even asked them to return the table, I still want it...I just want it working as advertised!!
Stuff like this really gets me going. I suggest demanding your money back or at least some back for the cartridge. I would return the table and find one here on Audiogon.