South American making fun of my spanish?

I dont know maybe because i learned from a Spaniard from seville spain. But i noticed when speak they understand but try to correct me when i use words like Sevilla = Sa-vil-la Cine = Cee-na and Zapato = Za-pa-to.. I make the S-C- and Z sounds when pronouncing these words but when i hear a south american say the same words, it sounds like they are using the C sounds for all the words?? Also when i use the word Vale = Ok they are like WTF?? Do Hispanics or south americans have a hard time understanding people from spain?