CALLS CEEP COMING! For maintenance plan!

I bought 2 Suzuki Swift's last year, it comes with a 2 year maintenance plan. The marketing of Suzuki keeps on phoning me about taking on another 5 year maintenance plan. It's on/off 2-3 days per week and the day they phone it goes like this. YOU GET ABOUT 5 CALLS THAN DROPS WHEN YOU ANSWER IT, WHEN IT DOESN'T DROP YOU HAVE TO WAIT FOR WHEM TO COME AVAILABLE TO SPEAK TO YOU! I REGRED BUYING SUZUKI SO MUSH BECAUSE OF THIS. I've take this up with Megan Macdonald "Head of marketing and PR" at Suzuki Auto South Africa but calls keep on coming. I've now sold the cars and even after telling Suzuki, CALLS CEEP COMING!