Hi All, Happy New year !

I am after some advice, my MMi unit in my A5 has just randomly started having issues, the radio has stopped working completely and any connected media plays but resets every 20 seconds which makes it pretty much unusable.
I have tried taking it to a local VW/Audi specialist in Basingstoke by they just said the main mmi unit had failed and needs replacing and gave me an absolutely crazy quote for a new one, it just didn't sound or feel right so I told them no thanks,
I have also checked all fuses and signs of damage in the rear passenger side compartment where the amp and Radio box is located and all looks fine and also ran it through a diag and it just said radio fail and a fibre optic error.
Can anyone please give me some advice on how to try and get this sorted or recommend a decent company I can talk to about this that's reasonably close to Reading ?
Many Thanks
Dan