My family hates my son's name

So we, my husband and I have decided to name our son Baltazar. He will be namesake to my husband and his father. Carrying the family name. We, as parents love the name. It has meaning to us. His family is Mexican as is mine.

However, my family is very American with tradition. Therefore, they don't approve of the name we have selected. They frequently pronounce it wrong on purpose. Make jokes about it. Call him "Thomas" and tell me to give him an American name. It's extremely hurtful. We are not changing the name. We are sticking to our guns. How do I get them to stop?