Cannot change PHP Memory Limit

I have set up MAMP and installed my Theme with no problem. The issue is that the system status says that the memory limit is set for 40M and recommends that I increase it to 256M. I have gone through the steps on how to do this, but it just doesnt work! I have done the following:

1. added the function to wp-config.php

2. changed the value for memory_limit to 128M and 256M in php.ini in the wordpress folder

3. created a new php.ini file in my root folder with the funciton to set memory_limit to 128M & 256M

4. modified .htaccess to change memory_limit to 128M and 256M

5. tried to set ini value for memory limit to 128M and 256M from wp-config.php

None of these changes the value and the system status still shows the warning and 40M.

If i change the value in wp-includes default-constants.php, then everything goes to hell and localhost does not load. Just a white screen and even changing the values back wont let it work. I have to delete that default-constants.php file and copy paste the original from my WP download back in, and then it works again with the warning of a memory limit of 40M

Please help! i dont know what to do. I have tried each of those steps individually and then finally collectively…

I am can attach screenshots of all of the files for your reference.