Money and parcel ****** by Jeulia

I order a ring from them on the 1st of january 2016, by the 18th the parcel was in south africa's customs and held for release. The customs wanted my proof of payment which i sent. I paid R2500 for the item, jeulia only submitted a $20 payment (R340) to avoid china's customs duties. SA's customs want a R1500 penalty paid for difference, jeulia refuse to pay for their mistake and asking for a refund only willing to give a 30% refund. I am to pay R1700 for no service or items.