thank you. Having reviewed the account terms and conditions and terms and conditions associated with gift cards, from strict legal point of view, I think this may be potentially problematic.
The terms and conditions associated with the gift card provides that: "By purchasing and using a Gift Card, you accept the following terms and conditions: Gift Cards can be used to credit your Deliveroo account and are accessible on the Deliveroo website or app within cities in the UK where Deliveroo is available. You may return non-redeemed Gift Cards for a full refund within 14 days of purchasing the Gift Card from this website. However, once redeemed, you acknowledge that no refund will be made."
Meanwhile, the general account terms and conditions provide as follows: We may also close your account if in our opinion you are abusing our Service (for example, by applying for refunds or credit to which we do not consider you are entitled, making repeated unreasonable complaints, mistreating our staff or riders, or any other good reason). If we close your account permanently we will refund any remaining account credit you have validly obtained from our customer service team or Application following any issue with an order, by applying a credit to your registered credit card, or if that is not possible for any reason, by way of a bank transfer using bank details (provided you have supplied them to us).
Taken together, it seems clear that having redeemed the gift card against an account albeit one that is blocked constitutes redemption and as such, the if card value does not have to be refunded or returned to you. At the same time, the account terms provide that credit will be refunded where an account is closed but it does not mention reference to gift card credit.