Sim top up only

I have £20+ credit on my sim top up.
I am unable to make or receive call. Error message says not register on net work.
Can I get some suggestions please. I don't know Labara contact to call from another phone.

Only number I have is from when customer services phoned me,could try this :
+44 20 7031 0791
All the best

Thank you

Basically I barely have money and my sister put my thing on auto renewal and they took £10 today and I really need that £10 back is there a chance of refunding it as my plan expires tomorrow on the 22 April?

Zayyan you should contact customer support for help, they will be able to confirm if a refund is possible and action it if so.