they give false information

I phoned cell c to find out if my Samsung galaxy s4 is still under warranty. Because the screen needs to be replaced. The lady told me yes. So I asked her if they can collect the phone, she said yes. They collected the phone on the 20th July. They send 1 quote through for R993. 82 for a new battery. We phoned them and said we reported the screen not the battery. Then a few days later they send the 2nd quote for R2239. 27 for the screen. I phoned Friday to find out why we should pay if the phone is under warranty and the lady said the warranty was until the 15th July. And the phone was booked in on the 16th July. So now I want to know why they said it was still under warranty. And why they came to pick up the phone. If it wasn't. This is unacceptable and unprofessional.