Visa extentions and the wait

I was just wondering about others experiences with visa extensions specifically, and how long it took for them to get approval. I'm waiting for my approval at the moment, and it's week 7 and They have not contacted me or anything, and I'm worried it'll go over the 8 week estimated time. Has it gone over for others? Is it typically done within? My extension required no other documents other than my passport, so I'm curious as to why it's already taken so long..