Unwanted nicknames for kids. How do you stop it?

It all started with my eldest daughter (she's almost 7 years old now) and from the moment she was born my dad refused to use her name because he hates it and thinks it is far too posh for where we come from 😕 her name is Isabella-Rose and it's so beautiful and definitely suits her but my dad calls her Shuggie, which is a old man's nickname in Scotland where I'm from. I've told him countless times how much I hate it and that she actually responds to it when he shouts it but it's always been his way as he doesn't care what I think 😠 he has done the same thing again for my youngest daughter, her name is Thea but he calls her Kojac and my niece gets called Murphy but her name is Karris 😕 my sister is having her first kid after trying for 10+yrs and they have picked the name Marcus as they are having a boy but my dad thinks the name is gay and nicknamed the baby skidmark already 😠 I'm honestly at my wits end with him and don't know how to get him to understand how much we all hate it and how insensitive he's being because he's also got his friends and colleagues using the nicknames as well and he's so smug about it 😕