Answer All Your Questions about Taobao, Weidian and Shopping from China. Search previously asked questions or browse by category below.
You should give the entity that informed you about the declaration issues a call. This could be a customs office or the shipping carrier if they are processing the customs registration for you (e.g. DHL in EU).
Ask them exactly what you need to provide to prove the value.
Usually they will ask for a proof of purchase, for instance a Paypal invoice.
In other cases they want to see screenshots of the shopping order.