would help if you gave more details of the kit etc. but I suspect you have two options:
1) Bin and start again as even if you do ferment down to 1004 you will only end up with 1.9% beer
2) Mix up a second batch but brew extremely short. split both batches and mix together - this way you would at least have something worth drinking from an ABV perspective, though you will have a LOT of beer - close to 40 Litres would be my guess... this is both a positive and negative depending which side of the fence you sit...
Good luck!