How to get an invoice if seller isn't responsive

[specialkmariah]

How do I combine my shipping charges as a buyer if the seller is unresponsive?

[eburtonlab]

Sellers are not required to combine shipping or offer shipping discounts.

[jacbarcollectibles]

Did the listing say the seller combined shipping?  Not all sellers combine shipping and they are not required to do this or to respond to you asking about it.