Sorry to hear you are unhappy @esoxian and understand it is frustrating , however it really is advisable to check on promotions as well as details about new Devices before purchasing. Does the S21 itself meet your expectations or not?
Obviously it is up to every customer to decide but I am not sure it is best basis for changing brands unless there were other issues. However obviously it is your prerogative. As far as mobile go obviously there will be a few options in the future but LG have stopped making new smart phones. https://www.techradar.com/uk/news/lg-has-officially-quit-making-phones-heres-whats-next#:~:text=LG%2...
I do not work for Samsung or make Samsung Products but provide independent advice and valuable contributions.
My Device- S21 Ultra 5G ( SM-998B/DS ) CSC= BTU , 12GB/256GB
One Ui 5.0,Android 13 .