Those statements do not contradict each other directly, but it's very clear that a commodity is not its own use-value, nor is a commodity its own exchange-value. Use-value is very clearly meant to be the property of a commodity to satisfy a need, and exchange-value is meant to be a property of a commodity to be exchanged for something in a given context. That obviously makes use-value and exchange-value in the latter senses not synonymous with the term 'commodity', nor with each other.
How are those contradictory? Or what other things do they contradict?
Those statements do not contradict each other directly, but it's very clear that a commodity is not its own use-value, nor is a commodity its own exchange-value. Use-value is very clearly meant to be the property of a commodity to satisfy a need, and exchange-value is meant to be a property of a commodity to be exchanged for something in a given context. That obviously makes use-value and exchange-value in the latter senses not synonymous with the term 'commodity', nor with each other.