Creating New Agent is failing to complete - resulting in loss of 2 credits each time.

I've followed the basic instructions and uploaded documents successfully but it fails each time. I've wasted 4 credits now, so what should we be doing exactly to make the Agents work?

For reference, I've uploaded 5 documents and they are under 15mb each (although the instructions state 20mb, seems like 15mb is the actualy feasible limit).

Additionally, is there someway we can get refund on credits to try the Agents? Right now it's just sinking credits.

I will keep trying and report back. Thanks.