Wanting to pay off my mobile early

[Westy1510]

I've got multiple phones which are coming to the end of there contract and wanting to pay them off early but getting error message 

I can post a screen shot if needed of the error message but it's leaving me frustrated 

regards 

lee

[Westy1510]

 

[caesarome]

To pay them off it is always est to call Sky on 150 to do this as it is quite easy to make a mistake and instead of paying them off you could easily add the payment to your account instead meaning the payment wouldn't go towards the devices.