Problem with mobile data connectivity after returning from Japan where I used e-sim, after deleting e-sim

I used a complimentary e-sim in Japan for data connectivity in Japan. after returning to Singapore, I did not have mobile connectivity for my local sim from SIMBA.

was only able to have whatspp and viber messages but couldn't download attachment like photos, screenshots, or videos.

tried accessing browser, netflix, youtube, etc - keep twirling but no access. tried accessing email - messages are not downloaded.

tried airplane mode on and off; restart iphone - done a few times; still didn't work.

removed local sim and reinsert local sim and restart - nothing worked.

challenging as i cannot do mobile payment like paynow, or grabpay

Thanks for your kind assistance