Let me see if I understand?

1. Your receipt says you have a 12 x 24 x 52?

2. The liner being shipped is 12 x 24 x 52?

3. You measured 15 x 22 x 52?

Hmm. The total perimeter on a 15 x 22 is 74'. The total perimeter on a 12 x 24 is 72'. Given that the ends are NOT actually rectangular (which my calculations assumed) that could be the SAME actual perimeter. Is it possible that your 12 x 24 was installed a bit woppy, and ended up a 15 x 22, roughly?

My recommendation? Call the original seller, the liner maker, and the installer and ask if it's possible you that you have a slightly mis-installed pool. If so, you may be able to make the liner fit. If they say no, beg for mercy and a refund from the liner maker. A 12x24 liner is probably NOT a custom liner, so they could take it back if they are willing. Tell them you'll accept a 60% refund -- but try to catch them BEFORE it ships.

Good luck!