Ive calculated the internal volume is approximately: 61700cm³
The rough dimensions of a packet of haribo are: 7cm x5cm x0.5cm
So the volume of a packet of haribo is roughly: 18cm³
This means that if the haribo were perfectly laid in there, you could get 3428 packets.
I doubt OcUK even have that many packets and i also doubt that they will be put in there perfectly to fill all the void exactly.
I estimate that it is loosely packed (for convenience) and so divide it by 10:
3428/10 = 343 packets
So, my guess is: 343 packets