Client promised to pay and did not: email template

Hi [Client name],

On [Date of promise] you let me know that invoice [Invoice number] for [Amount] would be paid by [Promised date]. I haven't received it yet.

Could you check whether the payment was sent, and if not, confirm when it will be? If something has changed, please let me know today so we can agree what happens next.

Thanks,
[Your name]