Dear John, I am sorry that you find it offensive that a robocall is speaking Spanish to you. I could easily blame it on our rather provincial and parochial culture.
You see, there are an estimated 548 million Spanish speakers in the world, many of whom live in the US. Spanish is one of the six official languages of the United Nations, and it is used as an official language by the European Union, the Organization of American States, and the Union of South American Nations, among many other international organizations.
Only 430 million people speak English as their first language, and English is today only the third largest language by number of native speakers, after Mandarin and Spanish. Of course when combining native and non-native speakers it is probably the most commonly spoken language in the world, though possibly second to a combination of the Chinese languages.
Considering that almost half of our language is Greco-Latin, in which Spanish is based, and nearly the other half Germanic, I can only lament at what must be your inherent indignance over being unfortunate to be born an English speaker. I'm sure you would have been much happier were you born native Chinese.
That said, these [***] call and say nothing as often as they speak Spanish or any other language. ...and silence accounts for more than half of any spoken language in one form or another.