Replacement seeds?

Today Katie and I went to the 'Farm shop' and purchased some tomato seeds.  Thought of trying to grow them in the garden and see what comes of it.  When we reached back home, I burst out laughing and I showed to Katie the following, printed on the seeds packets

Guarantee: Should these seeds fail we will be happy to replace them. 

I suppose they would have had some sort of logic to have them printed but I just don't seem to get it.  How does one replace planted seeds??  Does it mean that if they don't sprout, I'll have to dig them out, search them and then take them back to the store?

Really?