Gearbox ecu peugeout 307?

I have a peugeot 307 1.6 petrol.i tried start it and won’t go in any gear.its a semi auto.peugeot say it could be the ecu on the gearbox and want £2000 to fix but not 100% sure that it is it.Is there anywhere I can send the gearbox ecu to have repaired instead of paying the £2000