Endless junk mail from the Club

We sold our caravan last year and bought a motorhome.  The caravan was insured through the Club. When we changed I cancelled the caravan insurance, and insured the motorhome elsewhere as the Club's motorhome quote was way too high.

Since then I have received a stream of unsolicited, unwanted (and therefore junk) letters from the Club urging me to take out or renew caravan insurance.

They know we no longer have a caravan, so why do they keep sending this stuff?  Does it originate from the Club, or the broker?  Assuming I'm not the only one getting this stuff, how much does the Club spend on sending it out?

Interestingly, along with the latest junk mail I received our renewal invitation, from which I note the cost has gone up yet again.  Perhaps membership costs could be kept down a bit more if so much money was not wasted on junk mailings.