@NinaWildeUK: I'm sorry to hear that you're experiencing this issue. Please can you take a look at the link below, where you'll find a guide on how to wear the Galaxy Buds Pro. I hope this helps.
How to properly use the Galaxy Buds Pro | Samsung UK
@NinaWildeUK: 3 differently sized eartips are included with the Galaxy Buds Pro, in an effort to optimise the fit for every customer. I'm sorry to hear that you've not been able to find the right fit for you, and hope you're able to source a reputable, third party option, so you can enjoy your Buds to their fullest.