No need to buy another device as Im sure (If your patience won't run out), we will get your device back on track, running even better as it has ever before. But to be clear, you should know what we are trying to achieve:

1. Modify original (visual) interface, so you can run alternate navigation software (first step)
2. Replace original Mio navigation software with better alternative - iGO Primo with the latest HERE maps (second step)
3. "Fine tunning" of the new navigation software (third step)

These steps won't restore your device to it's factory state as there will be completely different visual outcome along with the navigation software which is far better as it is default Miomap sw.

And you are wondering about the reason why is your mio messed up - well, these things may happen sometimes when doing official updates..if some files are corupted or for some reason are not transferred correctly to the unit, you may end up with "soft-bricked" device and the result is your example. In the end that doesn't mean that device is permanently damaged and it can't be restored. We just can take advantage of the situation and transform "wreck" to Porsche and that was the meaning of my previous words..