Surface Laptop Studio Battery Replacement?

a while back my battery suddenly died on me and the laptop only works when plugged in . obviously this has become extremely inconvenient especially as a student but i also held off on purchasing another system for more intensive work and gaming has this laptop seemed to handle that very well and ran all the games that i actually wanted to play smoothly. since ive been using it plugged in the performance has been poor and struggles with simple tasks. gaming wise, ive even seen noticeable performance drops in games like minecraft and roblox which is a lil concerning lol. i bought a battery replacement thinking that i could simply take it to the shop and they could fix it but most shops refuse to fit the new battery or just charge something absurd. ive considered sending it back to microsoft but they have quoted me 500 gbp which is lowkey insane imo (maybe it isnt lmk). what should i do . what yall think i should do