AITB: am i the asshole for using my exes 7 brew account to get free drinks?

reposting this here because it got taken down on AITA

I (20f) and my ex (19f) were together for only 3-4 months and let’s just say i had more fun after the relationship was over than i did in the relationship. she would flat out lie to me about the littlest things (about her parents knowing she was gay, her best friends age, what she was studying for in school, her being cheated on when she was the one who cheated etc). she also cheated on me and threatened my friends because she “didn’t feel secure in our relationship”.

anyways during our relationship she would go to 7 brew almost everyday and get multiple drinks every-time she would go. and if you don’t know every 10 drinks you buy at 7 brew you get a free one.

so after me and her broke up, my best friend came over to you know help me get over it (i was already over it) and we went to 7 brew. i had the great idea because i was so used to using my exes phone number to see if she had any free drinks on her account that me and my best friend could use and they told us she had a free birthday drink and another free drink. so because of all of the stuff that this girl had caused me i used her birthday drink and another free drink on her account.

we broke up in march, but when my best friend came over again in may we decided you know what let’s try it again and we used her phone number again. so we got free drinks.

i don’t know if she has noticed but i am just wondering am i the buttface?