I'd agree with the above post about contacting them. My wallet was stolen the year before last and my medical exemption certificate was in it. I just rang them up and explained the situation and they sent me a replacement. For information, if you already have a pre-payment card and are then diagnosed with diabetes, they will not refund you. I had a pre-payment as I need a lot of asthma meds and I hoped it would be similar to getting a road tax refund but they told me they don't refund even if there is almost a whole year left!