Q: I have one icloud address on my iPad, and a different one on iCloud.com and can't change either one to consolidate my mail

I couldn't use my old @me address when Apple switched from mobileme, So I had to create a new one. That one is on my IOS devices, but the old address is still the one on iCloud.com. I can't change either one. Is there anyway to just use one or the other for everything?

Thanks for any help

Howard