I have to use the bonnet release a lot due to some battery issues but now the pull has stopped working. I've pulled it hard but not as hard as i can. 

I did see a U-tube video where they took the front grill off and then undid the bolts clamping the mechanism under the bonnet:

https://www.youtube.com/watch?v=p19PrFWTTQo

But there are posts on this forum that say you have to smash the grill.

I saw another video where they reached up from under the engine but there was another post here that said they couldn't see the lock from underneath. 

I am worried now that the battery will die and i won't be able to get in to charge it or be able to drive to a garage.

Please if you have any advice I'd be grateful to hear it.

Thanks in advance.

Steve

You're best bet is to go underneath. Smashing the grill is a last resort in my book. 

I had a bit of luck with this problem. Before starting to work on it I did my utmost to get the lever working. I bashed down on the bonnet with my fist a few times where the lock engages with the frame. Then I pumped the bonnet release lever using both hands, one on the end of the lever and one higher up on the stem of the handle, in and out and eventually it popped open. Then gave the mechanism a good clean and lubricate, also did my A6 bonnet latch for good measure while I had all the gear out. My Christmas present from Santa. 

That was lucky. Is the release mechanism now easy to operate or will you face the same problem again?