Dear random generic company,

When recently perusing your store I obtained an unremarkable mug that holds coffee about as well as any other mug in my possession for which I paid you $3. I believed the providing my card details and obtaining a receipt was the closure of our interactions on this matter. But alas my email inbox is repeatedly troubled by your misunderstanding that we have an agreement for ongoing engagement. You are of the belief that I am to provide you insight into the qualities of this mug about which there is little to say. Should you wish to engage my services for market research a formal agreement denoting payment in cash or gift cards shall be required.

Unkind regards,

Me