Horrible Service, with No feedback!!

Its been a month from were I received an order that was missing parts, and been returned for refund (225748) The order was collected, and no communication from Leroy Merlin on when they plan to refund my money. They do not even bother to reply on my email to them. Should I proceed with letter of demand from my legal team? I will not let Leroy Merlin take my money. I want my full amount back in my account within 7 working days, as required by law, and then I will proceed with legal action. I will also post my story to My Broadband to investigate their way of doing business. Facebook and Twitter will also be options. Customer service is not part of Leroy Merllin policy.