Dyson V8 Vacuum Regret After Painful User Experience

I bought a Dyson V8 vacuum from the store three days ago. I only used it once, and after cleaning just two rooms, my index finger started hurting. I've been trying to get help from both customer service and the store where I bought it, but it seems they can't assist me because I bought it in person. When we tried it in person for around 10 to 20 seconds, or maybe even a few minutes, my finger didn't hurt. But, when I used it for a long time, it hurt really bad. Dyson and Media Markt won't let you return or exchange this product. If you keep using this vacuum, you'll definitely end up with problems like stiff fingers or even worse. I feel really bad about spending so much money on this product.