What to do if I can't get a visa to attend a conference that accepted my paper? My work got accepted into a very good category in a very good conference in my field. Due to complicated visa issues it will be very hard for me to attend that conference. 

If I don't attend the conference they are certainly going to remove my work from the proceedings.

I am worried I won't be able to claim any sort of achievement if I don't attend this conference.

Can I still add it to my CV and specify that my work got accepted in this conference in a very good category?
If your paper gets withdrawn, then there may be no public record that it ever was accepted (and if there were, it could potentially be misconstrued as a withdrawel for other reasons). I can't say I've ever seen such an item on a CV.

On the other hand, even if you cannot make it to the conference in person, you can try to either:

a) have someone else give the talk in your place.

b) give the talk via telecommunication, e.g. Skype.

Both options are certainly not too unusual in my field (theoretical computer science/math). If you have to go for the second one, make sure not to leave contacting the conference organizers for the last moment, and be aware that this causes quite some work for them. If you can provide enough detail on your visa issues that it is clear that it's not just "You waited too long to apply", most people will be quite understanding.