how can i fix my fridge freezer?

aparently all frost free freezers do freeze up after a while, now the problem with this is the freezer still works fine when the freezer is froze on the ellements, but because the fridge uses the cold air from the freezer to cool the fridge the air is trapped and cannot circulate, but if you move the ellemant this apparently stops the problem and the fridge will work still. Is this correct, or will it just need manually defrosting when it freezes or can it be mended thx