With all due respect, that sentence makes no sense.
Even though I might assume that "quiedanzari" is a dialect word (from Sicily or Calabria, just guessing), I don't think such bad spelling could be put close to a verb like riscuotere. Therefore I'm confused. Who wrote that? Can you explain? I know what a power of attorney is.
I suppose the key lies in that "riscuotere", it usually means "to collect a sum of money", so maybe your relatives in Italy need to name an attorney to collect some money or have it back or who knows.
Quietanza is a receipt, a quittance.
I would like to help more, but I have the feeling we're still no nearer a solution.
P.S.: When you said "my family", did you mean the family you live with? Otherwise we call them relatives