Same issue here. Brazil, my ISP is Vivo and my traceroute logs show basically the exact same pattern (the 8th hop or so is a Telefonica node that sometimes doesn't appear, and around the 13th hop the packets just time out).

I tried contacting my ISP directly, but their customer support doesn't know how to handle this. They're only trained for common or menial issues that most standard clients have, so when I approached them with this problem, they just tried applying "standard protocol solutions", like asking me to check the wires, or the DSL line filters or other nonsense like that. Either that or they just dropped the call without warning.

So yeah, this is kinda hard to solve from our end.