Marshalls Wallpapers — wallpaper installation not as per selection

Address:

400101

Hi,
I have been working with marshalls since the last 3 years, never faced a problem,, however last time i got wallpaper installed from marshalls, they have installed the wrong wallpaper and now they are expecting me to bare 50% of the cost to replace with the chosen one.,
Scenario-
I shortlisted 2 wallpapers a& b to chose from (Of the same book - nature luxury)
Towards the end, we finalised wallpaper b as it completely matched my other interior colours of the room.

On the day of installation the person was requested to come by 2pm but i was clearly informed that lrior to 3-4pm installer wont come.
I had specifically asked for the installers contact from the branch manager, which upon calling was switched off. This is around 2pm to notify installer ill be reaching at 3pm and to reconfirm his timing.

My assistant reached site at 2:45 & called me that application has been goig on since 2! And the wrong wallpaper has been applied, i had the work stalled and inmediately contacted the respective store manager, who claimed the wallpaper is as per choice.
Now ;
The day the measurement team from marshalls came to my site,
I had specifically asked him to carry the respective wallpaper book,
He apparently found carrying the book difficult but got a swatch anyways.

The swatch matched the wallpapers picture that my client had taken and we okayed the order.
We have the swatch pictures and the wallpaper pic from the book as proof that our selection was that.

Marshalls team keeps bringing up code numbers.. But as layman i have nothing to do with the same as i have taken the designs picture for my reference.
Codes are their duty and not mine..
They refuse to accept a mistake has been made in noting down wallpaper
And are suggesting that they will replace it only under one condition - that we bear the 50% cost..
They claim the swatch that came was wrong.. But how can there be such a big co incidence that i have a samwatch thay matches the picture i had taken at marshalls showroom?
Kindly tell me why must i do the same when its. Not my fault..
-selected wallpaper b
-recieved swatch of wallpapwr b
-workers phone was switched off
-marshalls team notified of the wrongwallpaper
-marshalls not ready to accept the mistake
-no client servicing after an association of 3 years..

We dont mind moving this as an official complaint.
Kindly revert at
[protected]@gmail.com.