my sim doesnt have any connection bar on it,

[Janith]

I cannot pay my monthly bill how can I pay for this one

[Bambino]

@Janith See this guide: How can I pay my bill? (o2.co.uk)

Keep in mind that it can take up to 48 hours for any payment to clear O2's account. As you are paying on a Friday, and we are also approaching the Bank Holiday weekend it will take even longer. You probably shouldn't expect to have your service restored until next Tuesday at the earliest.

You can speak to the Payment Management Team on 0800 902 0217/0800 032 5302 but I doubt they will be able to get you reconnected any quicker. If you have no phone to use you can download Skype to call those numbers for free: Guide: A Guide to Skype 

The opening times are:

Monday to Friday – 8am to 8pm

Saturday – 8am to 6pm
Sunday – 9am to 6pm

https://www.o2.co.uk/help/account-and-billing/payment-support

You can also reach O2 via social media:
Facebook (https://o2uk.co/O2CFB), Twitter (now X) (https://o2uk.co/O2CTW), or Instagram (https://o2uk.co/O2CIG)