It's all Martin mate in your email, you come across as decent chap... etc, etc...
I'm going to leave this thread as engage no further, but feel a right of reply on behalf of Aquiss was needed. I wish you well.
Dear Martin, as a company director I'd like to offer my advice.... whilst I admire your efforts to engage personally with your customers, I feel you're not really helping yourself or your company.
Having a company director becoming embroiled in customer complaints on an online forum, for all to see, doesn't project a very professional image. Surely it would be wiser to leave this task to your technical support, customer service or complaints department to deal with via your company's normal channels.
I realise it must be very annoying and frustrating to witness individuals 'bad mouthing' your company on a forum, but retaliation usually just ends up making the situation worse. Maybe it would be better to simply direct them to your customer support department.
I hope you were able to resolve this customer's issue amicably and I wish you all the best for the future.