All you really need to know is: it's called ayuda familar, there is (currently) a limit of sending the equivalent of us$1500 per month to a direct family member abroad (don't be surprised if this gets reduced), and that your pesos will be converted at the official rate. You have to do it through your bank, your bank branch will tell you the details of what is needed, what is needed seems to vary from bank to bank, so apart from the basics that havew been discussed on the board, you're really going to have to go to your bank and talk to them. I don't know that you can do any of this with Casa Piano, anyone I know that has been doing it has done so through their bank accts at the regular banks.
From ours we have so far been asked for my birth certificate, a utility bill from my mother, her birth certificate since her last name has changed, our marriage certificate (since we will be sending the money from my husband's acct to my mother's acct). And then my mother bank acct details. Then our branch sends to central branch all of this, and central branch may require more info, so will let you know once we've gone through process. However, every bank varies in what they ask -- we first went to Santander and basically they had no clue and it was a pain to deal with, so since we also have an acct with Citi we are now dealing with them and they seem to be a bit more aware of the process.
The best advice I can give you is to go to your bank and tell the front desk that you need to talk to someone about sending ayuda familar abroad, they should direct you to the right person to speak to.
Part of the reason the banks are kind of clueless is because there seems to be different procedures for sending to an Argentine citizen abroad vs sending to a foreigner abroad, that's where the snags in communication have come for us. And also because things are slightly different from country to country, so what information they need from a Canadian may be different than what they need for a French citizen etc.
Will post more when I have any concrete result... right now our paperwork is all in transfer