Billed for Verizon service not received

Verizon telephone order taker said cancellation of my DSL service (Verizon online) would be triggered by disconnect of my Verizon telephone physical landline.

DSL is delivered on a landline.

Two weeks after removing the landline, I received a credit card bill with full DSL charge.

Verizon Online refused to prorate a refund back to date of landline removal, even though it was physcically impossible for me to have used the DSL service after removal of the landline.