Compatibility Spektrum DX2.0 and Mamba Monster

[orso76]

I tried with 3 trasmitter and relative receiver but my monster won't setup: Spektrum DX2.0 - Futaba 3GR Fasst - Hitec Optic6.
I tried these T/R with other 2 esc Mamba Max and all 3 work fine.
I think that my Mamba Monster is broke, so how can I do to replace it with a new one?
I buyed it 3 weeks ago from this site and it never work.

Thanks a lot,

Lorenzo