Is there a way to extend VoiceMail recordings expiration date?

The way Amazon Connect voicemail works in its expiration is the S3 presign URL which has a maximum of 7 days. The code has been fix to let you configure this, please read through the issue in github https://github.com/amazon-connect/voicemail-for-amazon-connect/issues/10

But your need is 2 weeks, the wav is there but the URL is invalid. So to do this, you will need to custom build some logic to immediately pull the wav file (S3 trigger), into SF. And have an expiration set using SF logic to remove the file. But please check if this will be compliant as the content is now being copied.

Other ways could be add additional code to generate another presign URL after 7 days for another 7 days, update the record in SF. You can potentially add this using a wait in Step Function

If you need to be able to get access to the recording past the 7 days (which is a max for the presigned URL itself, not the recording), you will have to change the way you access the recording. Instead of using the code provided with the voicemail solution, you can create a web proxy layer that creates the pre-signed URL on demand. So your email/SMS will have a link to this web proxy (that contains some identifier allowing the code to retrieve the right S3 object for the recording). When invoked, this proxy (web app) generates a pre-signed URL and allows you to access the recording this way. Because the presigned URL will be accessed within seconds, you can set a very short expiration time (30 sec) on it, and you will always have access to the recording, because the presigned URL is generated every time you click on that proxy link. You can then set the retention period for your voicemail recordings to expire as part of your S3 lifecycle. The proxy will also allow you to implement permission based access to recordings, so not everyone that has a link can listen to the recording. I hope this helps.