My mother acts as if she does not know?

So I'll start with my mom and I recently made a contract about how often I can use my ipad she had written one and asked me to look at it I talked in with my mother and we changed it a bit she said i should do it i did it all in all i was fine until she gave me a limit on ipad today i asked her what that is supposed to mean and she freaked out and said she never talked to me like that I can play so much and so much even though she has it and my dad believes her because it's his wife and she claims that I wrote it down even though I did that with her approval other examples are that she said I play a ps4 can buy and then she flipped and said she never said it even though she did and people she does not have Alzheimer's or anything

Please do not help me Weiss anymore (sorry for spelling mistakes)

She is just one of those people who are very confident of themselves.