Unless this person has cancelled on you multiple times before, it is possible that they have a totally valid excuse for not being able to show up. Being empathetic and flexible with your own time, especially when dealing with a client, is not only professionally appropriate, but will be deeply appreciated by the other person and reflect well on your company.
If you had to create time from a busy schedule to squeeze this meeting in, there’s nothing wrong with letting the other person know – especially if there wasn’t a reason given for the cancellation. You can do this without being passive aggressive by simply being honest – stating you were disappointed to hear they had to cancel, and that you’ll be busy for the rest of the week(or however long you’ll be busy for), and hope you can reschedule.
If the meeting that got cancelled was actually one that you’d been looking forward to all week, or an interview for another position at a company, don’t lose hope. Hiring managers can often choose to postpone interviews if they have too many candidates to see that day, and asking when the next best time to meet would be will show that you are motivated and confident in your ability to perform well. If your meeting’s been cancelled because the recruiter has found a more suitable candidate for the role, but you still want to work for their company, there’s also nothing wrong in stating you hope they may consider you for any other suitable positions, and to thank them for reaching out to you. Building a network is an essential tool for survival in the modern workplace, so showing that you are courteous even in the face of rejection can actually impress hiring managers, who may be able to point you to other opportunities.
Still unsure how to go about responding to a cancellation? Just follow this format:
I’m sorry to hear you won’t be able to make it, unfortunately I am busy for the rest of the week. I was looking forward to talking more about [reason for meeting], but I understand it may just have been bad timing.
Hopefully we can reschedule for some time in the future.