TomTom doesn't read?

I have a TomTom one, (V2) which was working ok,
As some of the new roads are not there, I tried to upgrade it via internet. As the old versions of some of the map files were adviced to be deleted, during the down loading proces; I did so (i was not being able to have a back up copy). During the file down loading process, it came up with an error message. Therafter the normal maps too didn;t work. Now unable to use it.
When the power was on by mistakenly the Memory card was removed. Now it too does not read..??
I bought a new card, need an advice, what I shuld do next please.