How to change ‘standard shipping’ times?

Hi everyone, just having trouble with amazon default standard shipping speed. It is defined as 14-28 days (which are business days), which is ridiculous. I cannot modify it, nor can I get rid of the standard shipping. I am offering a much faster shipping rate and 14-28 business day is just a downright lie and I don’t want to display it.

Anyone else faced this issue? If so, how did you fix it?