A lot of people leave Accenture and all the other Big-4 firms (both consulting and accounting) after their first few months to a year. They often switch to grad schemes in completely different industries. Obviously, you have to explain the change but there's no great shame in saying that you realised you'd made the wrong choice, and reevaluated your options. People understand that the marketing power of the big recruiter brands sometimes sucks people in (although you probably shouldn't say it like that in an interview).
The question is, can you see a route, or can you find someone to advise you on finding a route within Accenture to get to some work you'd enjoy? If you're able to articulate the work you're interested in then feel free to throw up a question on this forum about how you can get from testing to that field.
You'll probably find that when you have a clear path to get where you want to go, another six months of testing won't be as hard to bear. I would confidently guess that there's no way to get out of testing immediately without seriously damaging your reputation for reliability and hence your future prospects within the firm.
If you can't find a path within Accenture then certainly look elsewhere. It will depend on where your preferences lie what your plan of action should be, as the timings for e.g. taking a Masters, vs. starting your own business, vs. applying to banking are very different.