Ummm.. Pardon me... but as I was reading this my mind tried to connect some dots.. (and I could easily be wrong
) but... "Volunteer for 7 hours at thrift store" (not a normal *volunteer* type place).. plus extra chores... and my guess is punishment? If you are being punished for something, the best thing to do is get it done and get through it.
Second... not to sound terribly un-sympathetic, as I am... but your personal chores don't really count in a list of chores. I mean... think about it.. if your mom had to do her own laundry, you wouldn't count that with her chores, would you? You would still consider that she didn't do anything all day even though she put on a load of laundry?
So what I read is that you.... "volunteer" for 7 hours at a thrift store (not as long a shift as a paying job would be)... then you come home.. pets and personal hygeine aside... and you open up the fridge and cupboard onto food that your parents have paid for and make something you get to eat? So it doesen't sound all that neglectful of a situation to me. And then you clean up after everyone... that one I do consider a chore. A yucky one!
With the other children in the household of sufficient ages... it really sounds like a punishment duty to me if you are the one being singled out. BUT if it has nothing to do with punishment... you should request a more even allotment of duties. When I was a teen, we had a family rule that whoever had to cook didn't have to do dishes... (even mom and dad) so everyone had a chance to sit down at some point in the evening. Also no one had to cook or clean 2 days in a row, it was someone elses turn. That way it was fair for everyone.