One would think they would elaborate on their intent and why should I bear the burden of insured shipping on my earrings and the jackets???? That is expensive!
Is it international?
If they would have asked you to ship/insure your studs to them for the custom jackets - they wouldn’t have covered that cost.
Call them. Ask them to split the cost of shipping and insurance with you. On their account - ask for a label. That’s what I’d do in your situation.
Without knowing if they really charged you for custom design, rather than quote of an existing model with lab melee - it will be curious if the quote also changes.