Parcel never delivered & refund denied

After 2 months during which the customer service kept on asking me to wait for the delivery (due to problems with the customs, the couriers, etc etc), they finally admitted that the parcel got lost. Then I asked for a refund, but they said that the kind of shipment I choose does not include a refund. So I paid 20 pounds to get nothing. This is the first time for me that the vendor does not take its responsibilities for the shipment service.