3 days or 1gb , which ever come first BACK TO CAPPED SPEED
  u can RENEW ur package before expired for UMI package can get top up discount from me 

can for UMI package

just purchase another package and renew IF same plan

broadband package then can't, must wait expired

assuming you use top-up voucher RM50 + RM20, topping up on the same day 18-Feb, then it's correct.

RM50 = 100 days validity ..... so, 18-Feb + 100 days = 29-May.

the RM20 topup is "useless" cuz multiple topping up doesnt extend the validity back-to-back. It starts from the day you top up, i.e. 18-Feb and only the longest validity date is valid.

since 29-May is the longest validity, the RM20 (40 days) doesnt make any difference.

e.g.
18-Feb ----------------- [100 days] --------------------- 29-May
18-Feb ---- [40 days] --- 30-Mar
even if you top-up RM20 first, then RM50, the longest validity of either one will take effect.

all telco do the same anyway, cant run.

it's business for telco to make money from top-ups.

Tested yesterday, don't check balance quota, I used 40gb and try sent vol status to 22188, ix shows 0USusage of data, but start from that I check next time usage start to increase, then capped after 1GB

However the coverage are still limited, but it does improved alot compare to 2 years back which i last tried Umobile. Whole Sarawak only got one SC in Kuching. 

service
try out all the services (voice, sms, mms, internet)

location/coverage
test the connection speed/quality, coverage strength, etc. at your usual places, e.g. home (front, back, upper floor, etc.), workplace, lepak place, hiding place  , etc

time
try the services, at your usual locations, during morning, afternoon, evening, night, midnight, early vampire morning 
the umi28 package valid for 1 month (30 days), so test all these kaw-kaw within this period. if you're satisfied, port to umobile postpaid plans.

nope umobile 3g is using own 3g tower, only 2g network rely on maxis, u can see the difference when u holding 2 phones, 1 maxis and 1 umobile in GSC mid valley cinema, then u can see maxis 0bar while umobile3g on full bar, but honestly even full bar signal, at mid valley umobile data also super slow ..

probably no traffic or you're the only one hogging the nearby base station