Negative RP, Shaco-like IP, and the zed-less me

So, a couple days ago I went and bought some RP. No biggie. I wanted to buy thresh and his new skin (DS Thresh), because I love playing him, etc. Anyways, I purchased the RP without trouble, and bought Thresh, the patch didn't come out soon enough so I ended up getting Deep Sea Thresh instead. This is where things got funky. I bought Vayne with RP- my RP instantly went Negative. I had -492 RP, and actually I felt it was so peculiar that I sent some snapchats around about it. I reset my client, and logged in. I realized that my IP, originally at about 3.5k was just under 750, without buying anything with IP. Unfortunately, this meant an even longer time to save for zed. So sad, right? I'm not looking to get my IP back, tbh I really don't care all that much but I just want to know what happened and how it can be prevented in the future.

[zombie-nunu-bummed]