Data

[Joelucky7]

I’ve topped up but can only use my texts and phone calls can’t use data says no connection wen I’m trying to get into my apps 

[MI5]

@Joelucky7 

Make sure your data is still turned on in phone settings and reboot your phone.

Check guides Guide: How can I sort out my network issues? 

Guide: Is the network down for me or everyone? 

https://www.o2.co.uk/apps/my-network

[Oxonian]

What PAYG tariff are you on @Joelucky7 ?

A Rolling Plan or a Big Bundle ? 

It probably is not the answer to your problem, but it is worth bearing in mind that one of these tariffs - the £5.00 Big Bundle - does not actually include any data at all :-

Big Bundles: Eveything you need to know – Help and Support | O2

https://www.o2.co.uk/help/pay-as-you-go/big-bundles