I have sent an email to WU Customer Care to find out the official limits. Sadly, Argentina WU web page only shows the limit per transaction to send money (
https://www.westernunion.com/ar/es/send-money.html) per person per month: $ 239.000 ARS. Comparing with Colombia WU web page, where both limits are shown, limit for sending money and limit for receiving money are quite similar: 9500 USD and 7500USD, respectively (or their equivalente amount in local currency COPs). Probably, in Argentina, they must be similar as well (I mean limit for receiving money should be around $239.000 ARS). By the way,
@Macanudo mentioned something regarding this topic before:
"If you do a bank to bank transfer there is no fee. I was told several times at my usual Western Union office that the maximum monthly in-store pickup amount was around 300,000 to 320,000 peso per calendar month." I'll let you know the information as soon as possible.