Best payment mode for cab

The best payment mode for cab that  笨mummy discovered so far is the Nets Flashpay function of the OCBC Frank credit card. 

Firstly, Nets Flashpay auto top up (ATU) on OCBC Frank Credit Card can enjoy of 6% rebate if you can hit the minimum spending of $500. 

The use of Nets Flashpay allow one to enjoy a further 5% rebate on taxi fare if one spent more than $30 per month on cab. (See Nets Flashpay promotion: http://www.nets.com.sg/offers-a-promotions/nets-flashpay/taxi-rebate-flashpaycard)

See computation below: 
Assuming a monthly cab fare of $30, consisting of an average cab fare of $10 per trip.
cost:
Admin fee from using Nets Flashpay - $0.30 x 3 = $0.90

Gain:
6% rebate from Frank Credit card - S$1.80  [i.e. 6% x S$30]
5% rebate from Nets Flashpay - S$1.50    [i.e. 5% x S$30]

Net gain: S$2.40 (a 8% gain from S$30 spending)