Duties for a book to Switzerland?

This Monday I have shipped a book to Switzerland, with a courier .

Today I have received this message from the same courier:

"We are required by the customs authorities to collect taxes and duties from you before we can hand over the parcel to our partner for delivery.

You can easily pay this via our website using the link provided below."

When I clicked the link, I saw the bill:

Duties and Taxes (VAT): 7.01 CHF

Facilitation fees : 13.95 CHF

Total amount to pay : 20.96 CHF (about £ 18)

Amazon has already retained VAT 1.5 From the payment (total order £62, shipping £ 15.78) , I don't think I have to pay this. Moreover, the VAT is wrong and I would lose most profit.

The courier has also contacted the customer, who refused to pay.

I have shipped books several times before to Switzerland, with Royal Mail, and I was never requested to pay any additional duties.

I intend to ask the courier to return my parcel, then I will ship it with a more honest courier.

Any advise or suggestion?

Guy