What does it say on your receipts? If the points are not on the receipt, then they are unlikely to magically appear on your Clubcard account I would think. I am not sure what Clubcard would be able to do if you contact them "pro-actively".

Next time, I would buy a maximum of £100 gift cards per transaction per checkout.

Do online vouchers get the bonus CC points? Also, will Next tills be able to cope with 25 gift cards? I know Debenhams can only take 3 gift cards per transaction, so when I was trying to make a large purchase, I had to buy several items less than £150, then refund them onto a single gift card, multiple times before being able to finally buy the item I actually wanted