Change EDGE to LTE

That is already set to LTE/WCDMA/GSM its in About Device - status - Mobile Network Type that EDGE is showing and I think it should be LTE which is why my mobile data is so slow - My carrier is BT (British Telecom)
 
could be the reception is poor in your area or maybe your carrier does not have lte there. check that your carrier has lte in your area and also if your sim card is 4g compatible
 
The carrier BT confirms that 4G reception good in my area and that the card is 4G compatible - its the "Mobile Network Type" under "Status" showing EDGE that is my concern.

I think EDGE is 2G.

Mobile data does work but extremely slowly.

How can I change Edge to LTE?