I ordered an item online from a US vendor via a credit card. It arrived to me one month later, but it was the wrong item. I informed the vendor of this, and they offered a partial refund. This is not acceptable to me as a customer; I was sent an item I did not pay for, I want a full refund. The vendor refuses to provide this to me. Can I have my bank cancel this transaction since the vendor charged me and then delivered a different item?
Yes. You can file a chargeback with your credit card company. Call their customer support line and tell them that the merchant is refusing to offer a refund and they can reverse the transaction. The merchant will then need to decide if they want to dispute the chargeback.
The credit card company will just want to know if you've made an effort to work things out with the merchant first, and it may be worth mentioning this to the merchant first to give them one last chance to issue the refund. Chargebacks can hurt the merchant's reputation with their CC processor if it's a recurring problem.
Note that chargebacks should be used appropriately. This sounds like an appropriate instance. If your CC company believes you are filing too many chargebacks and trying to commit fraud, they will cancel your account.