Excessive Data Usage by System Services on iPhone 13

[Stoker]

Over the past couple of months I have been exceeding my data allowance. After some investigating I have discovered that System Services seems to be the main culprit using around 75% of the allowance. I have been on the Apple support forums and checked all the settings to minimise data usage. Today I got in touch with Apple Support and they recommended that I should raise the issue with TalkTalk as in their experience the issue lies with the carrier. 

Does anyone else have this problem or have any advice that they can offer.

Apple want me to get a "Ticket Number" that I can pass on to them if I don't get any resolution with TalkTalk.

Many Thanks

[KeithFrench]

It is surely the phone that is using the mobile data, not the network provider. I agree with @Gondola on this.

[Stoker]

I've done all that but it still doesn't answer the question as to why system services is using so much data and there is no way to control it other than switching off mobile data.

[Stoker]

TalkTalk is my network provider and I now switch off mobile data when I am at home but obviously need to have it switched on when out and about.

[Gondola]

I always switch mobile data off. I switch mobile data on when I need Internet access but am out of range of Wi-Fi.

You can set apps to update only via Wi-Fi. You can set apps that can only use Wi-Fi.

I suggest you switch off Wi-Fi Assist as this automatically uses Mobile Data if the Wi-Fi signal drops out.

[KeithFrench]

Is TalkTalk your network provider for this mobile? Have you tried disabling mobile data on the phone?