Which effectively were the same as Mr K's here

(OP was also curious as to how normal people offer loans and get repaid...I answered that they don't, if they have any sense. By all means help out a friend or relative, but don't ever expect to be paid back)

AND WAIT A SECOND.

OP - you sure as heck changed the numbers around, didn't you?!

(PA)
So my ex and i split up and right before we did i went to the notary and had her sign a 40G promissory note, i figured it was counting ALL the money and effort i spent on her from the beginning of our relationship till 6 years after. The note states that she pays monthly (around 800) for about 4 years.
7 months later and I'm finally over her but i'm still paying for some things that were once hers (phone, joint credit card etc.) I came to the conclusion that i only want 15G back because that amount was the official amount that i paid for her credit cards out of my pocket and the rest of 25G was just us blowing it together on going out and doing coupley stuff. Mind you that she hasn't paid me back a single cent and she's going around saying that she doesn't owe me anything. To top it off, we're still both young and i'm finishing up college. Since i never been in this situation or thought that i would be suing someone who i once loved dearly, i need a guide on what to do, i don't know where to go or what to say for that matter. Legal advice is what i am seeking, but moral advice is greatly appreciated as well (besides devastated i am confused as well)! Thank you much in advance!
Pick one. She evidently didn't sign both - and now I'm wondering if you actually had a firm number at all, given that it changed willy nilly in the space of 24 hours. It's starting to sound like you don't actually have much at all, and you're testing the water to see how much you can get away with.