HOw to contct customer service abroad????

I am in Argentina. Supposedly I would get free roaming for Data and text. But it did not work at all through operator MOvistar.  Called the 1 800 number and talked for 2 hours. THey made me change some settings, and still nothing. Then they made me re-start phone. I said that I would then miss the call They said they would call em back. Received no call back at all and now when I try to call again I get message (in Spanish!!!!!!)  that the same call I made 1 hour ago I am not authorized to. WTF ????? But these brainiacs at TMobile do not have email  chat service, only phone.... BUT THT DOES NOT WORK AND THAT IS THE REASON FOR MY CALL!!!!!  Still they want me to verify my identity through a code that they sent to ... my phone  !!!!!! But I do not get txt there dummy, again, the REASON WHY i AM CALLING!!!!!! WHo designed this crap!!!!!!!!!!!!!!!   WHere do I contact Customer Service through internet (from somebody else, not my crappy T MObile that DOES NOT WORK !!!!!!!!!!!