Multiple payments done to Directory Services

We have been paying a lot of money for this so called company.We have never made use of this service.When we email them and ask to cancel everything by them we never get any feedback.I only received like twice feedback from them and since then they are still sending me invoices like: Yellow SA,2018 Editions - SA National E Directory,Directory listings for prints etc. We made for this year payments of up to R8000.00 to them.Now we received and invoice again a few months later on saying that we have to pay R4800.00 to them again.When we contact them on their number that is on the invoice it does not go through.They say if we are not going to pay they will take further steps.

I have a good feeling that these people are a ****.

Please help.