The accounting team (is dedicated) to providing accurate billing statements within 24 hours.

why (dedicates) is wrong? what difference is?

See a translation

Using "is dedicated" is good:

"The accounting team is dedicated to providing accurate billing statements within 24 hours."

But using "dedicates" is not really wrong, if used like so:

"The accounting team dedicates itself to providing accurate billing statements within 24 hours."

It's a subtle difference.

The first sentence describes a characteristic about the accounting team, that is, it is dedicated to a cause (providing billing statements).

The second sentence describes an action that the accounting team does, that is, it dedicates itself (to providing billing statements).

And here is something more to think about:

The second sentence would sound more natural to a native US English speaker if "itself" was replaced with "themselves", like so:

"The accounting team dedicates themselves to providing accurate billing statements within 24 hours."

"Itself" agrees in number with "accounting team" but "themselves" agrees with the number of people in the accounting team, presumably more than one person. This is typical of a difference between British and American English.