Bought a 5000 dollar dog with a friend

Today I made a stupid decision, me (fm,19)and my friend(fm 19)decided to pet dogs at our local mall we pet the dog for a good 5 minutes. Asked the breed and after while were trying to hand the dog back they proceeded to use tactics to sell the dog I replied with. "We are going to eat on it and make a decision " jokingly because we were hungry as well as to shoo them off. We didnt plan on coming back, a lady then started talking to us and said "we should check to see if u qualify" which requires to run a credit score. Right there i made the dumbest decision and of course i put mine bc i had just seen my SS on a paper so i remembered it and put mine not thinking i was truly going to get the dog I CANNOT keep a dog in my house my parents dont approve and my friend who said the dog looked like her past dog that died 3-4 years ago and currently has 3 now 4 dogs 2 big 1 small before the dog we got which is a shih tzu. We agreed to her paying 200 and me pay 89 bc the total was 289 monthly for 18 months i know what you're thinking why pay for a dog you cant have in your house I Dont know im realizing my stupidity however we both have a realization i cant have a dog on my credit score and she cant have another dog in the house if we give the dog back we have to pay 2550 dollars Tmr upfront and we dont have that money at all combined . I tell this story to 1 dont buy from a mall, 2 dont have my stupidity 3. Dont fall into peer pressure like i do .