on 01-01-2020 10:06
If you are trying to get back a refund then you can only do this by contacting customer services
If it's a refund of a £300 deposit you paid, then it should be returned to your bank automatically after you have paid 3 months bills on time. It will be paid back onto your 4th bill.
If it hasn't then it's still customer services you need to call as we have no access to your account here.
Best of luck, welcome to the forum and Happy new year
on 01-01-2020 10:13
How to get your deposit refunded here https://www.o2.co.uk/help/account-and-billing/refunds
OnePlus 6 (O2 & Sfr), Z3 Tablet (Three UK), iPhone 8+ (EE)
on 01-01-2020 14:15
It can take anything up to a month if it's for a phone you bought and returned. Just keep on to customer service.