This one is a little bizarre.
Pepsi have rebranded themselves as "Pecsi" for the Argentinian market. Pepsi is one of the world's best known brands, and changing brand names is not something global mega-brands do lightly.
The issue in Argentina is that locals have already been calling Pepsi "Pecsi" for a few decades, because "ps" is not found in Spanish. English words that contain a "ps"a tend to become a "bs" in Spanish. For example the word "apse" in English is ábside in Spanish. With this logic, most Spanish speakers pronounce Pepsi as "Pebsi."
In Argentina however, they speak a unique dialect of Spanish, which won't even allow for "Pebsi."
Pepsi has decided that as people in Beunos Aires and beyond are so used to ordering "Pecsi," why bother fighting them? Pecsi it is.