EHIC cards cost nothing, anyone charging is scamming, and with BREXIT looming their value is limited
The Great EHIC scam
Money for old rope, or even less

Applying for an EHIC (European Health Insurance Card) in the UK has always had a loophole for a "legitimised" scam. The card itself is free to apply for if you do it yourself online, but companies can legally offer the "service" of applying for you. They need all the same information, which you input online through web forms just as you would applying for yourself, following which they take a payment (for their services, *not* for the card, although they only make that clear in the smallest of small print and try to imply differently) and submit it just the same as you would. So what are you paying for? Nothing. You still have the same inconvenience, just paying for the privilege.
Anyone who has had an EHIC before - even if you applied yourself direct - will have been bombarded with mail by at least two of these companies nearing its expiry date, because the Tories mandates that the NHS had to make the data available for sale. They bombard you with dire warnings of expiry, and strongly advise you to renew through the web site they give you, all very formal and business-like never once reminding you you can do it yourself for free.
Now, in present times it gets worse still. With the end of their gravy train looming, they're pulling out all the stops to try to wring every last penny they can out of the scam. They are once again exhorting people to renew before the end of this month (which is nominally when the NHS will stop issuing cards), but now they are spamming everyone they have an address for, regardless of whether the card is due to expire. And here's the real kicker: if you hold a valid card you CANNOT renew, but still they want to charge you for the privilege of applying. And of course, even if you do get a new card now, there is very little chance a UK issued EHIC will carry any merit come January 1st.
If you want a card before September is out, and don't have one, get it yourself: https://www.ehic.org.uk/