You are flat out wrong. I can't prove a negative but you CAN prove a positive. Show me the EXACT part of Mitt Romney's plan that backs up your statement. You can find a link to his actual plan in the article posted in the first link.
Mitt Romeny's plan raises NO ONE'S TAXES. Not the rich, not the poor, not the middle class...no one's. Here is his own plan for individual taxes from his own website. As you can see no taxes are being raised and the people in that article used assumption, not fact, to come to their conclusion.
Tax
"Americas individual tax code applies relatively high marginal tax rates on a narrow tax base. Those high rates discourage work and entrepreneurship, as well as savings and investment. With 54 percent of private sector workers employed outside of corporations, individual rates also define the incentives for job-creating businesses. Lower marginal tax rates secure for all Americans the economic gains from tax reform.
Make permanent, across-the-board 20 percent cut in marginal rates
Maintain current tax rates on interest, dividends, and capital gains
Eliminate taxes for taxpayers with AGI below $200,000 on interest, dividends, and capital gains
Eliminate the Death Tax
Repeal the Alternative Minimum Tax (AMT)"
^ not one of those raises taxes on anyone be it rich, poor, or middle class. To say otherwise is dishonest.