This is a very common complaint, although it is based on a misunderstanding, as Spotify does not censor music in any way (search for your favourite curse word if you want a demonstration of that). Any music that has been censored was submitted like that.
Albums are very often released and submitted to Spotify in two forms: the explicit version, and the clean (censored) version. Often, the only visible way to distinguish between these two versions is that one will have an "Explicit" sticker on the album artwork. Consequently, Spotify will consider them to be identical.
On the Artist page, the two albums will be collected together. One of the albums will be visible, the other one can be revealed by clicking the duplicate arrow that you see to the far right of the album title.
Spotify make available all the content which is given to them by the record labels. If the uncensored tracks are not available, get in touch with the record label and ask them why they aren't on Spotify! You might also be interested to read this FAQ about missing content.