I don't recommend attempting a 3rd time only because the S8 replacement falls in line with the warranty terms and conditions. Part of the terms state:
- We will provide you with a a reconditioned device of like type and quality. If not available, we will replace it with a new device of like type and quality.
Have you given our Care folks another shot at getting you a replacement phone? Please give us a reply and let us know how things are going.