Bolero radio random changing

Hi Guys

Can anybody out there help please.

The radion in my 2012 Greenline Octavia keeps randomly changing to other stations when the TP is switched on. It isnt going to other traffic reports, just random music, talk or white noise. Traffic comes through ok when it comes up on stations.

If I switch TP of this does not happen.

After a major battle getting the dealership to believe me with 2 visits to download the memory for any fault indicators(none found) and a discussion regarding them finding the fault I got a call saying they would have to have the car for 2 days while one of their techs drove it to see if they could replicate the fault. Amusingly I then got a call saying that as they had driven it out of the workshop it had changed channel all on its own! Therefore new radio could now be ordered. New radio fitted, problem still there, new ariel system fitted, still not resolved.

Car has now been in 5 times and is going in again this week, Can anybody suggest a solution as I dont think the dealer really know what to do next and I rea;;y would like this problem to be solved.

Thanks

Greenline10