I've just been on line to renew our EHIC cards, and was directed to a website claiming they issue the card. The final page of the web asked for a payment of £14.99!!!
I obv did not pay this as the cards are free. 
I went to the NHS web page and applied for the card online for FREE through them, but there is a comments page at the bottom and it seems several people have paid something between £9.99 and £14.99 like I nearly did.
So apply for your card through the NHS web site and it will be free - here is the page I used.
www.nhs.uk/NHSEngland/Healthcareabroad/EHIC/Pages/Applyingandrenewing.aspx