Buying a Skin Twice?!

I recently bought 5000 rp, (I had 5046 because of leftovers) and bought Master Chef Tahm Kench. Then I played a fun game of Jax, which led me to buying SKT T1 Jax. However, My Rp suddenly decreased to 2571 instead of 3321. I believe this is because the RP used for Jax got duplicated and made me pay 1500 instead of 750. Please fix this issue and give me back my rp. The document has 2 pictures that will prove I bought the skin and rp.