Hi eCommerce people.
I create signs, decals and similar products (sometimes T-Shirts, Mugs). What goes into the sales value is of course materials, labour, packaging, machine maintenance and complexity of design etc.
When a package is damaged or missing, how do I 'prove value' or 'certify value', as the shipping companies like to say, when I'm the one making it? I'm based in the UK if that makes any difference and this come about because I sent some wall art pieces to a customer and they were crushed by TNT. I sent them the invoice as a 'proof of value' which is what the customer paid but they asked for 'actual cost' and offered about 30% of what I actually sold it for, plus refund of shipping fee after sending them some invoices showing per metre material costs etc.
Now I understand they should be replacing the value of the item TO YOU, not what was paid for it, but 30% was less than my costs not including my time and they did not want to accept anything else.
On this occasion I've taken it on the chin so I can get on with other things so…
How do I better prepare for that in the future?
TLDR; Proving value lost to shipping company as a manufacturer / creator. How to mitigate losses?