I might have mentioned it before, but if I haven't I recommend a very simple app on your phone to keep track of them. I know you're not much into phone apps, but for others that might be it could be good option for keeping track of the card balances. There probably heaps of options for tracking apps, I'm currently using Giftcardy (no affiliation in anyway), which doesn't require any unusual phone privileges (eg it doesn't need access to your contacts
) and is quite easy to use.
I'd be interested in others thoughts on easy ways to track remaining balances on these offers - it can be tricky.
I also get rid of any small remaining balances at one of our friendly supermarkets - although I wouldn't recommend Aldi - they seem to only allow one card transaction per "checkout session"