Won't stop spamming me

I mistakenly half-filled an application on the Specsavers website. I abandoned it halfway when I read about the insane interest these guys charge. Not 30mins later, they called me. I said to the lady that there is no mistake, if I wanted to complete the application, I would have. Worse still, they now won't stop spamming my email inbox daily, WITH NO WAY TO CEASE THE EMAILS, NO WAY TO "UNSUBSCRIBE" OR OTHERWISE END THIS MADNESS.