I also have had many calls on this number.
Call 0800 282 390 and insist you speak to someone who knows about the 084-530-0727 number. It is Barclaycard!! If you have no joy at first ask be connected to Barclaycard in the UK. Keep going until you get to someone who will acknowledge the 084-530-0727 number is a Barclaycard number. No need to give any of your details even if you are with Barclaycard other than your name & phone number.
I have just spent 27 minutes on the phone, hope that's the end of it.