45W MagSafe 2 Power Adapter not charging MacBook Air

I just got a new charger for my 2015 MacBook Air and all it comes up is that “Battery is not charging.” I tried the charger with another MacBook Air I had and it said that it would take 8 hours to finish charging. I had bought the 45W as it said that it would be compatible with the early 2015 model of MacBook Air, however it has not been charging at all. Is there a way I could fix this? If not, would I be able to return it and get a charger with higher Watts?