I've sorted things out - here's what I've just posted in the other place.
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What you need to do is go to Settings->Connectivity->Settings->Destinations.
On my phone, the tick was against WAP services.
Just press Options->Default Connection and then select "Internet" and the tick is now against Internet settings.
So that was the first part.
Second part is harder. Click on the Internet option, which showed 5 entries. The order was
My Wifi, Contract Wap, PAYG WAP, Contract Internet, PAYG Internet.
I wanted
My Wifi, Contract Internet, Contract WAP, PAYG Internet, PAYG WAP.
I have achieved this but it took a bit of doing.
What you have to do is gently, slide your finger across an entry you wish to re-prioritise. So I did this and a couple of times it moaned about it being a protected entry, but once I got lucky and a menu popped up. From that I selected Change Priority. Nothing appears to happen. What you have to do is then tap the item you want your previously selected to appear above. So I tapped Contract WAP. Lo and behold, I had Contract Internet above Contract WAP.
Follow this procedure for anything else you want to move.
For good measure, I rebooted the phone, not sure if that's necessary, but at least I won't have to do a factory reset.
Regards
Neil