Reselling what you have purchased is legal (so long as in buying it, you did not sign any agreement or accept any terms of sale barring resale). However, you cannot use their logos or trademarks in advertising the clothing without their permission (which they can freely withohold; and if they grant it, generally involves some licensing fee). No one can use someone else's trademarks without the trademark-owner's permission, even to sell the trademark owner's goods.