You can try to request a refund via the website (although 90 mins is an acceptable schedule change to them - even 4 hours is acceptable). So you'd have to be forceful and speak to several agents.

But they only refund in the form of a credit voucher, which can be used towards future Air Asia flights, and must be used within a certain time, 90 days if I remember correctly. And it will take a minimum of 1 month to process.

As quoted from another thread recently,

"They don't listen to complaints and they don't have to because they don't care"

If the earlier flight is really that inconvenient, book a new one.