Bad service

I joined netstar and all was fine while they were debiting up until the cancelation after 3 years. I never missed a payment and they charged me a prorated premium at the beginning, that means I was paying upfront. No one bothered to explain what needed to be done after contract expires. They kept debtting me every month up until I realize that, and I called them, they said I should have contacted them after expiration this was now in November 2022 and contract expired March 2022. I then instructed them to cancel and I did let go of November debt order. They went to debit again in December then I reversed that debt order. In January 2023 debt collectors were calling every day for for that payment. I was annoyed. I have been calling Netstar to resolve this issue but each time I call they promise to call me back and no one came back to me.