Hello and thank you for your question, it is very important to us.
I have read the question and the background provided my colleague Ben
What is it you would like to know about this? Is it just what you should do at this stage, if anything?
Ok - then you dont need to enter into protracted correspondence. You have made the offer to refund and that is it.
You dont need to keep sending letters. If he does not accept it, then it is up to the customer to issue a small claim. You can then defend it.
But verbal agreements are binding, just like written ones. Written ones you have a paper trail, but that is not to say verbal ones are not binding.Can I clarify anything for you about this today please?