help, please

Hello, this is a guest who bought a pair of sneakers last weekend from your online mall and they were delivered yesterday.
I put on them but they were too big and their color was mistaken what I ordered.
Can I speak to someone in charge of service?
What you’ve just heared about my calling is about your product which I ordered.
I surely ordered a pair of sneakers usual size with black color.
But other product was delivered.
I don't know why this happens.
I have to put on sneakers this weekend’s marathon tournament.
Once in a while, this situation occurs but this time, it's too late exchange other product so I should refund them.
Can you help me?
If you would like to have time, please call back to me as soon as possible, thanks.