My cheerleading coach scammed me ...wtf?

okay so i tried out for the cheerleading team and i made it..woohhooo.. and i also tried out for band...so like im in both ...i only cheer for basketball season, normally the money is due during basketball season which in the second semester...nd band (dancer) money is due during the first semester so i had i thought i had time to come up with the cheer money b4 the second semester ,since i had already had the band fees...so the cheer lady tells us the money is due now..we had to pay a 50 dollar deposit , so after me and my two friends paid ( we were the only ppl who paid at the time) she send home a letter the next day stating the final cost 300 bucks..WE DONT EVEN GET TO KEEP THE UNIFORM. and there isnt no way i can come up with 300 more dollars after i just paid 297 ... i want to quit now because im not paying that ****....how do i quit... im 17 by thee way