Debit memo Blank Title 106858

We are trying to issue a 'debit memo' for a service we provided to a customer. They put an order in for custom product and we performed a service on that order usually added as a misc charge. The hitch is, the customer has become unresponsive and we want to close the order, but still charge them the misc charge. Obviously we can't have lines and we won't really be shipping anything so how do we invoice them for that service?