Where can I get the replacement HEPA filter?

My hoover stays on the 1 charging led but does not charge or turn on. Is there any way to reset it?

On the handset of my Grundig Cyclonic VCH9832, air also leaks out of the slots by the on/off button and through the opening at the top of the handle (for locking to the vacuum cleaner handle), so not only through the ventilation slots provided for this purpose. I think this makes the performance even worse. I didn't think it was that great otherwise. Is this air leakage normal/has anyone experienced it?

And what do you recommend now? Should you throw the vacuum cleaner away straight away if the filter is no longer good???