I think I wasn't given vivera retainers, I'm really confused

I did Invisalign moderate for a bit more than £4750 or ~$6000, and I was given my retainers 1 day after the scan and was told to come back in 4 months to check that they're working.

Is this normal? The case is generic as well. Am I entitled to vivera? I'm happy to pay a bit more if the retainers are better quality, since I also grind.