Marshalls Wallpapers — Worse service ever, took advance and have put the wrong material and refuse to correct their mistake

I decided to go to Marshalls for wall coverings as they have been in the market for long. I called their showroom and asked for a home visit consultation. After following up for over a month, someone named Samir came and took measurements in 2min without any proper discussion and advise and left. I had taken pvc wall covering catalogue pic at their showroom and showed him my selection and asked for the same to be put.
Wallpaper he said someone else will come and show designs. After much following someone came and I gave selections and asked for estimates for an additional room.
No response on the same. The PVC put was not the one selected and the room decor is looking terrible. When I complained Mr Samir put the blame on me and said the PVC put is what I had chosen! Such arrogance and rude behaviuor and refusing to accept his mistake.
Wallpaper work too has been left incomplete.
I need a resolution as innumerous calls have been ignored.
I want the pvc removed and correct one installed at no cost.