Bad Experience with Singtel DASH

on 7 Jun I use Singtel Dash successfully tap into Queenstown MRT but unable to tap out the Yio Chu Kang MRT. The station manager check my singtel dash and not able to find the details. In the end he manually lift the mrt gate to let me out. After that i afraid the same problem would happened again and decided to use the net FlashPay card to take another bus to my workplace that cost me $0.83. On 8 Jun Singtel charge me $1.63. Meaning the total journey costed me $2.46 instead of $1.71. On the 8 Jun send the feedback but no reply. Call the help desk today, the staff Rzaci ask me directly liaise with SimplyGo for the error in deduction. This is the customer service that the Singtel DASH provide. I dare not to use SingTel DASH for the public transport again.