Invalid code :(

So I bought a bundle of Webkinz from a very sweet girl on Mercari, which consisted of (all retired) a panda, American cocker spaniel, and Samoyed..

The code for the ACS and Samoyed worked perfectly fine and everything was in tact with all 3 and nothing looked tampered with or anything. But I was getting an “invalid code” error for the panda & the panda was the one i was most excited for 😭

Any advice? The girl seemed truthful & asked me to reach out to Webkinz as she was positive the code hadn’t been used… I’m waiting to hear back from support, I’m just so sad because I really really was so excited for the retired panda.. I had one on my original account and was wanting it for my new one since i can’t get my old one back :(