We are in the process of updating your account. These updates take at least two weeks to complete.
Please clarify this... does this mean that it will be done in 2 weeks or 2 week or more ?
From Merriam-Webster's definition of least:
1 : at the minimum
// at least once a week
In other words, if you say at least two weeks, you mean that it will not take less than two weeks.
But you haven't said anything about it not taking more time—so that's still a possibility.
So, when you say at least two weeks, you mean two weeks or more.