Bought Ringconn Gen 2 Cybermonday in the same size as my Oura G2, but it's too big, can't exchange at sale price. now what?

I saw that they were $199 on Cyber Monday but didn't have time to order the sizing kit. I saw a few older posts here saying they ran pretty true to Oura sizing, so I ordered the same one.

Well, today it got here and it's too loose. The only amazon options are to exchange it for exact item (same size) and refund it, but then to order the new size would be $299.

Is a ring sizer possible? I assume not, that it would mess with the sensors.