Daycare gets my child’s name wrong,

Lu

So my twin daughters have been going to daycare 1 day a week for 2 months. One of my daughter’s is called Oswyn, her twin sister is called Riley, Now for some unknown reason they have taken to calling Oswyn, Winnie, Her name is Oswyn and we call her Ozzy as a nickname. Whenever they come out to speak to me, they go oh Winnie’s had a great day. I’m like who’s Winnie? Despite me telling them on multiple that her name isn’t Winnie, it continues. Now I don’t know if I’m particularly difficult, I just don’t think it’s that hard to call her by her given name. They might think Winnie is a cute nickname but I don’t, nor do I feel that Oswyn is a difficult name to say. I get Oswyn is a bit more on unusual side but I think it’s a beautiful name. I just don’t know what to do anymore.