There is an expression in the UK "Cutting your nose of to spite your face" which I think you are doing.

By not following through, the only person to suffer is you...as you have a keyboard that will not accept the Upgrade (and any subsequent OS releases) that you have paid for.

Frank cannot be expected to solve this by himself. Granted, your distributor should have acted and Ketron should have understood your email. However they have not and you still have a keyboard that is working, but not able to update. (I don't think there are any other faults are there?)

make the call Leif.