I was ****med $300 through false advertising

I shipped a Parcel using UPS United States, This parcel was shipped from the USA to South Africa. I used the worldwide expedited package option, which I was told at the UPS office that the price includes a door to door delivery, customs, insurance and shipping costs. The total amount paid was ($198). Tuesday, I received an email from UPS in SA stating that I need to make an additional payment ($300) for customs clearance and duties which is very shocking because that was not the initial arrangement/agreement with the Importer. on top of that SA offices advised me that If I don't pay these customs within 5 days then my parcel will be auctioned.

How do you guys resolve this? If I knew upfront that the price did not include customs then I was not going to proceed with UPS. I feel that I am being treated unfairly as the shipping company has shared incorrect information with me regarding the shipping and delivery of my parcel. I am now at a risk of losing my expensive parcel.