I am unable to purchase anything for some reason
With a debit card or with paypal.
With the debit card it reports card declined, with paypal it says "An unexpected error has occurred. Your purchase has not been completed".. Mmm, helpfull.
Will have to wait for Steam support.
Could some kind sole please assist me before the daily deals expire?
You tried deleting the .blob? Or ringing the bank for that matter, sounds like its your debit card thats the problem.