Vox telemax is abusing me

I app**** for a inline contract with vox. Their consultant told me that i do not qualify for the deal since tgere is no coverage in my area. As a result, i then app**** for another service provider, and i was granted my contract.

After a week, vox sent me a sim card (the one i was told they can not give me because there is no coverage in my area) i then called then to tell them that i do not want their sim card since they denied it when i app**** for it, plus iv already taken another contact with another service provider. I even asked them, how should i send their simcard back. I was then told that i should just destroy it, and i did as i was told.

The problem now is that they call me non stop demanding payment of something i never used. I really need help to resolve this issue