... Peter in sunny Queensland, Australia
Shipping charges from DigiKey in the US might be a factor. If you bought these at a local store that carries a limited selection of TVS diodes, find the clerk that assured you the SA24A+ would work and swap them for the SA33CA+ . That's what "assured" means to me!
The markings on bidirectional parts should contain the letters "CA" (not just "A") and there should NOT be a silver band on one end.
Out of curiosity, did said individual tell you which way to install the banded TVS - whether the banded side goes to center or outer-rail wire nut? You can install the bidirectional TVS either way.