I already said in an old post that their terms and conditions does cover them excluding top-ups of Ezylink prepaid cards from 10x of UOB PPV. It would either be under "transport" or "money transfer". They can use either of those to "disallow" 10x on top-ups to Image/FEVO/M1 cards. And they also have the generic statement at the end that they can disallow any online merchants at any time.
It will be very hard to argue against them.
Just be grateful that they stopped awarding 10x earlier rather than later so that you guys stopped topping up your cards earlier rather than later. Just imagine if they let you happily continue topping up for another few months and then clawed back all the UNI$ you would be in an even worse state.
Dont give them ideas. You never know which UOB staff is lurking here and we dont need to to their job. Anyway there is no transport restriction in TnC. The restriction in the TnC is "Travel". Money transfer is also quite debatable. The issue is whether by representing that the transaction is qualifying by awarding 10X at the first place and lured people to spend more subsequently, do they have the legal and moral rights to come back to say sorry, i make a mistake and i clawing back all the bonus. I remember got some insurance case where the judge ruled that it is not right to assume that the consumer would continue with the activity had they known that it is not qualifying.
Just like you buying stuff which say X% would be provided (excluding certain category of items). After buying once, which qualify for the discount, you continue to buy the same item. A few months down the road, the shop collected money from you and at that point say, sorry, this product does not qualify for the discount as indicated in the terms. I will not refund you the excess money you just paid and it will be use to offset against the discount that you enjoyed previously.
the correct method in such situation should be a prospective disallowance and not a retrospective clawback.