Car problem, Gas related 2008 Scion xB?

OK my problem is, i was headed to work Monday night, i work third shift, i filled up my car at a local gas station non-brand name its like a mom n pops country store type thing, got half way to work.. started to have problems... long story short next day i get a call from car repair shop they say i have bad fuel... my fuel pump is fried and my gas tank has warped they cant even get the o-ring back on... the scion is under warranty but! they do not cover this type of damage I contacted the supplier for the corner store they said they checked and the problem is not with them, they said there gas is fine they came to store etc etc.... and the corner store is saying oh.. well i don't know what the problem is or how this happened saying that hes not had any problems with anyone else etc was also told that they have no insurance to cover it.. i was quoted $1,400.00 in repairs for my scion for a new gas tank, pump & labor what.. should i do i don'tt have the money to repair it please help