App**** voucher and still overcharged

I have bought items on the app and app**** the voucher BUY1GET1 voucher and the full amount was taken in my account p*** been sending email with screen shots and scanned all the evidence that I have app**** the voucher every time I call i get told that it will be fixed since September and when I send the email with the attached evidence they ask for it again then no feedback i have added the screen shot also have scanned documents i got on the tfg onlineshop that clearly shows i have app**** the voucher will this issue ever be sorted this has been going for too long please check the evidence of app**** voucher in the emails I've been sending