(Q) Fast charging doesn't work?

Had my S6 edge sinceand

Thursday, never noticed fast charging ever working, always said "cable charging"

I'm still within 14 days so I've contacted my provider

Things I've tried
- pushing the wire fully in
- plug to plug
- different USB cable

I'm on 5.0.1 stock
Any ideas anybody or exchange?

Also, what percent should I get from 15 mins charge on 5 percent?

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