i subscribed to a 4G sim only plan. But now I'm suffering because of the extremely slow speed internet. I having an unlimited plan but it seems unuseable this few weeks
I see that you are using an iphone. Would you like to try to reset Network settings on your iphone? Not to worry it will not reset all your data away, just the network settings.
Also , maybe you can tell me which APN did you set the iphone to. shwap will seem to be the better choice. Alternatively, if you have another starhub user side by side you, you can get him/her to do speedtest with you to see if its the phone problem or not. You can put your sim card in another phone to try too.
Lastly, if all else doesnt work, you may go to the main shops where they can help you diagnose / change a new sim card for you. That should be it.