Unhappy with Lenovo AIO bought

My work Lenovo AIO had to be replaced due to lightning damage. It was a S500z and I requested guidance to a similar or better system from FirstShop sales. I use this system for Cad/Cam design and a high resolutions screen is a must. When you draw a line at an angel in Cad and it's displayed with steps the system is not suitable. After spending lots of money the system I bought was found not to be suitable for my applications. It's been over two weeks now and I still have the new unit in it's box not being used waiting for the answer from FirstShop if I can replace, upgrade or return this unit.