If I recall correctly, I dont think they provide voucher redemption for treat fair. They might have ask you walk over to garden on the spot redemption.
I think the 250=rm1 is the conversation rate for you to buy items from merchant/store there, not on spot redemption.
correct me if i am wrong.
THis maybank very sien, during feb, said 400tp=rm1 after 1st March. Then everyone go and queue to change all to voucher, either mcd, gift card, aeon.
then few days before 1st march, changed it to 1st May. Then within these 2 weeks, everyone rush and queue again to change all new TP to vouchers again.
then now said Jun treat fair still can use old rate,

.
If they tell this earlier, I rather accumulate all the TP 1 shot buy items in treat fair, rather than change a lot of voucher s..

..Purchased items in treat fair can earn TP, gifts and lucky chance to win more TP/tickets
It is depend on how you treat it.
If Maybank immediate kick start the treat point to 400TP=RM1 on feb, you might complaint why no give chance or longer period for customer to redeem. I would say Maybank try to consider customer who do not have time to redeem now and it seems want to attract customer to redeem it asap.