Radagast was not excommunicated for his actions against druids. Being a stern campaigner for his punishment and then later for his excommunication and dishonourable discharge from the Order of Light, I am more than associated with his actions. Specifically Radagast was excommunicated for 4 specific and one non-specific breaches of the Codex of the Church, which the minor crime associated with it was not honouring his word ... lieing. So I believe you should really do some more work on learning your "truth". As previously stated, any member of the Order of Light will more than happily help you seek that which you lost.
Consider that last bit of info a gift of "truth" from Aurora.

Penned by my hand on the 23rd of Glacian, in the year 270 AF.