Repair service let down.

I made use of Mat & May's repair service for a pair of Oakley sunglasses which I purchased years before when they were still known as Matrix. I dropped the sunglasses off at their cavendish square branch/kiosk on 22/01/2016 and was told that it would take 2 weeks to a month to resolve. It's may already and still no rep**** sunglasses. The employees at the cavendish branch claim to be having issues with their supplier, Luxottica, who is the parent company for the Oakley brand. Surely if you know you have these issues you would as a company take steps to see that no delays are experienced by your customers. Today when I enquired for the 100th time where my sunglasses are the staff have no answer. This has gone on long enough with no resolution and I want the area manager to get into contact with me to find a solution. If no one comes back to me I will get legal help.