I suppose it is safe to top within 90 days after the credit validity is expired.

very disappointed with umobile prepaid plan.

1. deduct my credit for no reason

2. 1st time call to customer service admitted that is their technical issue. the lady say they will refund before my expiry date. So i'm being nice and i trusted her and waited almost 1 month.

3. now almost until my expiry date they never refund back my credit

4. 2nd time call to customer service and they accuse me that i renewed for the unlimited internet twice. hence it was deducted. argue for almost 10 minutes. then only the customer service admitted that they having technical difficulties during that period.

5. 3rd time they provide me a case ID and it seems i have to wait forever to get my missing credit. what the..

6. i never exceeded 500mb nor seldom using any of the free call / sms. what for i renew the unlimited internet twice

Umobile..i am so frustrated...!!!