Yes, it's true, also
HERE it says that at the end of the month it's NOT renovated.
BTW it didn't work with Cosmote? It worked for me with Cosmote in August, while it was not working with other Greek operators. Wind has BIG problems with roaming since April, and they are doing nothing to solve them....
Also check on your 155.it account if you were billed correctly, since in the seldom moments when I could use data outside of Italy I also payed the double (like in CZ last week)...