WiFi 3G problem on downloading application iPhone

Hi,
Was trying to download some application (games) from App Store by using wifi, but it tooks me for 2-3 DAYS just to complete the application? What is going on? Even if im using 3G, the problems is still the same.
Was trying using 2 different iphone 4 to download the same application at the same time, mine is the worse (2days) to complete it. Anything happen to the hardware devices or ... ??? dunno
Went to Maxis Centre to check out the problem, the technician told me that its nothing to do Maxis, all they can help is to change again the new sim card for me to try again, but the problem still the same. Not solved yet.
Is any fellow iphone users had the same problem with me?
Can anyone out there .. can help me !!!!