Wrong Package still in WC

Our company has been struggling for almost 2 months to get a package the delivered wrongly back to us. Their driver asked for a certain package and was given to them, only for them to deliver this to the WC and to the wrong company. Our company paid for the correct package to be sent down to WC and they said they will return the incorrect package to us. Only for their driver to send the package we just sent down to WC at our cost back to us. The incorrect package is still in WC and now they are refusing to take accountability for this and will not correct their mistake and send it back. Never before have we struggled like this to get a mistake sorted out.