I'd leave him a voice mail saying you wanted to set up an appointment. Could it be he mistakenly thought you'd set something up before he left? If this is an unusual thing with him, then I'd say reach out to him and try to schedule. If it's a common thing, then still reschedule, but talk to him about how much it affects you.

Has he been helping you in general as a T? If so, then give him another chance. If not, then still maybe give him another chance, but start looking into new T's in the meantime...