If you made the broker aware that you were a civil servant and already in a superannuation scheme at the time, then I think you have a valid complaint. But you do say in your first post that you were "stupidly" unaware of this.
Normally it's not possible to get a refund of contributions to a private pension arrangement until retirement. However, if you never should have been in it in the first place, Revenue might authorise a refund.
If the broker is at fault, then ask the broker to write to Revenue explaining the position and asking for a refund to be authorised. If you are at fault because you did not give the broker correct information at the time, then you can write to Revenue.