Faulty s9+ and watch

I took out an s9+ by cellucity with the watch combo not even i the second weak i had battery faults and the galaxy watch charger was faulty when i wanted to take it back they wanted to send it to samsung for repairs but i dont understand how can a two week phone go in for repairs its unfair that we pay so much for certain thing but some companies dont care what they give you for what you paying as long as they get the money and now im sitting with a **** pho e whos battery doesnt keep long not even half a day for a samsung s9+ with a faulty watch .. i just want to know how can i take it further cause im not going to let my money go to waste with an unhappy phone contract