[bayok]

I tried to SE some protein powder and read that SEing would be easy if saying the contents turned bad. However I got a response to upload a picture. I did so and I received a message saying I needed a doctors note saying the content caused digestive issues for any further complaints.
How do I proceed?

Claim that going to the doctors office costs more than the product, and that if you go that you want to be reimbursed.
Unless you already claimed that you went, in which case ask for reimbursement anyways.

As for avoiding submitting a doctors note, I would suggest using the corrupted image method.