"To Whom it May Concern at J.C. Penney:
I saw that your May 2012 catalogue has a homosexual couple in it. It is your company and livelihood, and as such, is your choice to run as you wish. I neither agree with nor approve of your effort to normalize and legitimatize homosexuality. As such, I will not purchase any merchandise from your organization, and will recommend to family and friends who feel as I do, to refrain from doing business with you as well.
It may very well be that this is a calculated marketing decision, but that would be too generous, especially in view of the role Ellen Degeneres carries out for your company.
There are many people who feel that promoting homosexuality is harmful to the individual, to the family, and to society, and I am one of them. If you wish to promote homosexuality as a normal and healthy lifestyle, you will do so without my support or my money. I normally would not welcome the bankruptcy of a company that pays people to work for a living, but since I see your open and enthusiastic support of homosexuality as morally bankrupt, I can only have the point of view that your company should lose the financial means to assist in the cultural erosion of society. And I say that with regret, considering the many employees who surely work for you who feel as I do, but have to accept your advocacy as a condition of keeping their jobs."
Your letter is well-written and should be well-received, however there is a problem: I think that you wrote this via email.
May I suggest that emails are a dime a dozen. The way to impress some company is to write a snail mail letter on nice stationery. I believe that companies read those kinds of letters and often respond to them. They likely will not pay much attention to an email, which they think (correctly) is often just knocked out at the moment.