What are the meanings of おはようございません and ありがとうございませ ん?

Nobody seems to say those things.

I want to know the meanings of おはようございません and ありがとうございません.

Answer

I would like to add a bit to the Earthliŋ's answer. Such standard phrases as "Good morning" are not taken at literal value, they are formulas to express some figurative sense. What is the literal sense of "Good morning"?

"This morning is good", or maybe
"I wish you a good morning"

And what does it actually mean?

"I greet you, and it is morning"

So, when you inflect such phrases, they immediately lose their figurative sense, and come back to the literal one, which is then inclined. Thus, "Ungood morning" would sound nothing like "I do not greet you". So the deeper level of the question is, maybe, What is the literal meaning of such expressions like おはようございます and ありがとうございます? And that is easy:

おはようございます = polite of はやい = lit. "Early", meaning "How early do I meet you!"
ありがとうございます = polite of ありがたい = lit. "Thankful"

Now you can easily deduce their negated meanings yourself. These forms -おう are unusual for beginners, they are rare, except for several everyday expressions.