Does the case have any hairline cracks at all? If it has any, even in the the slightest, bring it to an Apple store. They will replace it for free. Its a known manufacturing fault.
They even replaced the front bezel which I had damaged when changing the inverter cable. It was a mess. It was held on by duct tape. Yet, they still changed it.
Also, they put a new keyboard in it which means a new trackpad too. The total cost was 0.
I initially brought the Macbook and charger in to the store because the Magsafe charger had a loose connection and would sometimes not work.
So, bring it in. The store I went to was a reseller, not a proper Apple store.