My MS thesis advisor wants me to delay my graduation for one semester. What should I do?
If you don't have any problems with graduating next semester then just do that.  It will give you more time to refine your submissions and to prep for the defense.  A little annoying, granted, but it could be a blessing in disguise too. 

As for working with your adviser, what's done is done.  Perhaps they were delayed in their responses but you may have to accept some of the responsibility here as well, I think.  It takes some time to make all of the arrangements for finalizing graduation.  It's not like undergrad where they can just look at the transcript and say "120cu, good to go". Heck, just getting a defense scheduled can be a major undertaking.  Especially if you're trying to squeeze in under the wire.  Stack the university processing and thesis review times on top of that and you're really cutting it close. 

I can certainly understand your frustration (my M.S. was delayed by a semester due to a similarly inane set of circumstances which led to all kinds of fun) but my suggestion to you and anyone in a similar situation is to take a deep breath, relax, and use the time that you have to prep as best you can. 

Aside: This type of advice question is not a very good fit to the normal SO format.  I wanted to provide a response since I suspect that many people have gotten into similar situations but have fair warning that it may get flagged.