"I was given unclear instructions."

During my appointment for my echocardiogram, I first asked for my mum to leave the room but instead the staff member took it upon themselves to just draw a curtain even though when I inevitably had to walk out from the curtain my mum would see me. I was then asked to take off my top half clothing and then put on an orange cape that ties at the front, I asked the staff member what I’m actually supposed to do with it because I was very confused as there was no sleeves like I had expected and they was saying to put it over my shoulders so I did and I walked out and they said I needed to take off my sports bra too. I said is there no way I can keep it on and they said no because the gel needs to be rubbed on the heart area and they pointed to where that was on themselves and it would be right under the nipple so this to me as an insecure 17 year old girl rang massive alarm bells so I refused the whole thing. I wanted to wear a gown not a cape that would reveal and show everything, the staff member said it’s the least invasive test but the cape only covered my back whilst my whole chest would have been exposed and if it was supposed to cover my front then there would have been no way that they could have rubbed the gel on. This was all very confusing for me and I wish I was given some clear instructions. Afterwards they attempted to guilt trip me by saying how it’s one of the least invasive tests so they was confused why I wouldn’t cooperate but from the instructions given I was expected to walk out in front of the staff member and my mum with my boobs completely out which is something I’m not prepared to do. The whole thing was a mess.