Hey you still might be able to use it. I have made the same mistake more then once :/ . If you plug the battery in your charger and charge it as a NiMh. Watch it charge and wait until you get at least 3v per cell. Then stop charging and charge it as a regular LiPo. Good luck!
Just a little safety note ** If you make the same mistake (which I have done in a momentary lapse) and decide to attempt use of the battery be sure to examine the wire connections at the cell tabs. Shorting the wires by cutting both at one time provides a high possibility that those solder connections will have come apart (de-soldered). It's very likely the battery itself will remain unharmed as the solder joints should fail prior to smoking the cell(s) itself. That said, after repair, it remains wise to closely monitor the battery during the next few charge cycles.
Have been using a couple of these for approx. 3-4 years for ie. my Indoor Clik. Great performance and approx. 4-5 minutes flight time (depending on how lean you fly). Charge them in less then 30 minutes with the Turnigy 2S balance port (5ports) charger.
Can absolutely recommend these.
~Micro losi~ fits the following micros.
1/36~ Desert truck, High Roller.
1/24~ Rock crawler, Trail Trekker, sct, rally and truggy.
I have used this battery in all of the above and strongly suggest. If its not on the list it will not work unless you plan on modification.