Ross TV wall mount - 25-50” (Radlett WD7)

We bought this kit but it's the wrong size for our tv. It's not been used - still in its original box and the kit is complete (all the bits including screws etc.) and all in brand-new condition - although we did open the box before we figured out it was the wrong one. Details on the B&Q web site https://www.diy.com/departments/ross-black-swivel-tilt-tv-bracket-23-50-/22...