Beste antwoord door David
It seems you have been in contact with a service number, but not on May 21st, but on the 27th of April. Can you retrace this phone call on your cell phone? Service numbers often charge extra costs, on top of your minutes. Spanish is not my strong suit, but the number +5117900611 seems to be from Movistar. This page also states that there are extra costs, but since I'm not sure what it translates to, I can't give any specifics. : http://www.movistar.com.pe/negocio/moviles/tarifas-roaming-internacional
Costs being charged on your invoices are always calls that have been registered on our network. We won't charge you for calls that have not taken place!
Hopefully this gives your clarity, but if you have any further questions, don't hesitate to ask!