G'day Wildbilly,in answer to your question "If the mining cost...

G'day Wildbilly,
in answer to your question "If the mining cost is $7/T, and the processing cost is $13/T, how come the cash cost is only $15/T?"

If you go back to the report, you will see that Cash Costs are expressed in ounces of Silver not tonnes of ore.
When one takes this into account and converts the Mining & Processing costs based on a grade of 64grams/tonne you will see that Mining costs calculate to $3.89/oz
Processing costs calculate to $6.32/oz.
So a total of $10.21/oz.
Now add to this Administration, Overhaeds, Bank interest etc. you will now see that a cash cost of approx $15/oz would be pretty close to the mark.
I hope this helps.(& I hope I'm not missing something obvious here:))
Cheers,
Conman.