How to verify a 02 telephone call

[Supag]

I’ve had a call from 02 saying that because I’m a valued customer I can have 12 months discount on my phone charges.

how do u verify this is correct or is it a scam

[gmarkj]

It is VERY unlikely that the call you received was from o2.
Why would they call a customer and offer a year's free service?

I hope you didn't agree to anything @Supag ?
I would be getting in touch with customer services myself, either calling or using social media - all numbers and links are in the guide Guide: How to find help & contact O2 

It might also be worth checking out the Guide: A Guide to Deal with Spam/Scam Calls and Text 

[Bambino]

@Supag 100% in agreement with @gmarkj 

If you agreed to anything, see this:

If you think you’ve been the victim of fraud – whether it’s because you’ve given details to someone over the phone, or clicked on a link in a suspicious text or email there are things you can do:
Contact your bank if you think you may have given out financial information. They can help protect your account and stop transactions.
Change your account and online account passwords. Not just your O2 account. All of them.
Forward fraudulent texts to O2 for free on 7726.
Contact Action Fraud on 0300 123 2040.
Call your Virgin Media or O2 customer services number if you think somebody’s taken out a contract using your details.
Virgin Media customers can phone 150 from their landline or 0345 454 1111 from any other phone.
O2 customers can call 202 from their O2 phone or 0344 809 0202 from any other phone.

You can block the number that called you, or any number you think may be suspicious.

How to block a number:

https://www.samsung.com/us/support/answer/ANS00062352/

https://support.apple.com/en-us/HT201229

There are also these links to look at:

https://www.o2.co.uk/help/safety-and-security/phishing-and-smishing-advice
https://www.o2.co.uk/help/safety-and-security/unwanted-calls-and-messages
https://www.actionfraud.police.uk/

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)