Insensitive and *********** agents insisting on calling when I am in a Meeting

When my Contract was due for renewal, I was repeatedly called with offers for Renewal. When I explained that I was looking around, they would call me back twice a week to try and get me to renew my contract. The final straw was when I was in a Meeting (Online) I was called again, I said that I could not talk and was in a meeting, and put down the phone. 30 seconds later I was called again by the same lady, agent, as if I had never spoken to her. I have requested that my contract be cancelled, I am fed up.