Change an order

I am so frustrated with Dell I hope someone can help me. This morning I purchased a dell laptop for my daughter and she needs this ASAP for summer classes. After ordering, I realized that it doesn't have enough memory to last her the next 6 years in college and want to change the existing order and purchase a better computer since Dell is having a great sale now on the more powerful computers. The problem is that I can't purchase the better computer until the money is refunded to my card. One rep I spoke with says that I will have to return it once it comes then wait for a refund, another is arguing with me telling me that i won't be billed until it comes (which is NOT true since it already cleared my account) and my order status says it hasn't even shipped. Can someone please give me a number to someone that can cancel this before it ships, and I miss out on the sale of the better computer? (Not to mention that I will bro sending my daughter off to college without a laptop since the one ordered will not work for her)