I swapped vouchers for double value at my local Tesco store,bill came to £85.67 and used £80.00 in vouchers,when checking bill later I find I have been over charged by £5.97 for a Moon Sand craft product,as on the shelf it was priced at £9.97 and came up on bill as £15.97,this was not noticed until we arrived home and I telephoned the store to be told to take back the goods and receipt,when we drove back and waited for half hr in queue we where told the price was correct,it had been changed overnight to what they are saying is the correct price,now I know I may be getting on in years but I know the price was £9.97 as the vouchers are for multiples of £10.00 once doubled up and I had calculated the amount in toys would be £80.00 in vouchers and possibly a few pence over,no response from e-mail to Tesco,so feet are doing the walking to Morrisons or Sainsbury's from now on and extended family will do the same.