Ok - yes, if you were told £53 then that is all you need to pay.
I would also raise a complaint. You can do this by writing to:
Customer Relations Manager, Churchill Court, Westmoreland Road, Bromley, Kent, BR1 1DP
They will investigate the matter and report back to you. If they do not uphold the complaint you can then go to the Financial Ombudsman.
They offer a free, independent service and can examine your complaint at: www.financial-ombudsman.org.uk
That should resolve the matter for you.
Can I clarify anything for you about this today, please?
If not, I would appreciate a 5-star rating for my answer. If you need anything further I am available for a follow up at no extra cost.