Travel Makers (Wowcher) stating they can't provide flights at paid price, where do we stand?

Basically, 2 × Wowcher vouchers for a 3 night trip at £149 pp were bought and then immediately gifted for a family member. All details put in.

Family member redeemed following steps and then waited for Travel Makers to reach out per instructions.

Travel makers called and basically said they didn't have anyone's info except mine (original purchaser) and because of that they had to check if they could even secure the seats on the flight as they had originally used my info to book them. Which is fine, but then why offer a gift option if this is going to be an issue?

They did the usual attempted upsell and when declined they have come back and said they can't get seats on the flight now as we didn't reply to an email (that they never sent).

They are now insisting that the additional 99pp be paid to secure flights, or they look at different trips.

Can they do this? If they really can't provide the original quoted flights at the price paid, are we going to be able to get a refund?
It all just seems like a huge scam but I don't know where we actually stand on what to realistically expect and what is reasonable to push back on or whether we just need accept the loss.

Any advice or personal experiences of dealing with this/a similar situation with this company is appreciated!