Missing credit

[Anonymous]

My husband has a simple pay as you go sim, he may make 1 call every 6 weeks or so. However, when checking his balance, £6 has gone and no calls made. Is there anyway we can track where this credit may have been spent apart from call, thanks in advance 

[MI5 · Accepted solution]

The only way on PAYG is a "subject access request" which costs £10 so is impractical in this case.

http://www.o2.co.uk/help/safety-and-security/how-to-get-a-copy-of-the-information-we-store-about-you
Most likely explanation though is mobile data being on and using credit for background tasks.
Turn off mobile data and just use wifi for internet, emails etc and it will preserve your credit.