0113 519 6039 Negative Who called me from this phone number?

This is 100% a scam. Confirmed by O2. People acquire your email address and then attempt to login to your account. When this fails, they send "request pass code to reset password" this then pings you that text with a "one time passcode" to reset your password. This part is probably the 1% that is legitimate as this does happen when you a request a 1 time passcode. 99% of the scam is they do that, then call you saying they're from O2 or whichever provider and there's either a problem with your account or they want to apply bonuses. They want the passcode, you give it to them and they go into your account, change all the details and purchase things through your phone and rinse your account. If someone from your phone provider asks you for any details hang up.

Was told they were phoning from currys PC world before hanging up

Told me they from O2 and offering contract savings etc. Also told me they would send 2 texts, first was security, 2nd would have a code which I should give them. Very suspicious, call supposedly from Leeds but difficult to understand. I told them I thought it was a scam and wasn’t interested- caller said ‘OK’ and hung up. Worryingly the texts were from O2