Post office 6.9% existing customer offer

gkb_2

I received something in the post from the Post Office offering a 6.9% balance transfer and also I think offering that when any existing offer expired it would go to 6.9% rather than go to the normal rate. Not a great offer but if I can leave the existing balance there at that rate it suits me.
Problem is I have lost the details and cant be sure thats what it said, did anyone else get this and can confirm I can just let my current 0% finish and it will go onto 6.9%

Thanks