Convert text to columns will not work

My bank sends me my monthly statement as a csv file which I have quite easily copied into excel 2007. I want to be able to use some of the data to assist in producing my annual tax return.
The problem I have it seems the amount's in the 3 columns listed credit , debit and total are not numbers but text. I have tried most of the suggestion's listed on here to convert these columns to currency or accounting but nothing seems to work. Doesn't matter how the cells are formatted nothing changes, Iv copied a cell containing 1 and pasted special multiply to all the cell concerned but the cells refuse to change.
I have attached a small section of the workbook, I just want to be able to do calculations on the cells containing numbers.

Many thanks

Hi, Many thanks for replying so quickly even on Christmas day. I understand what you say and tried what you said but couldn't get the paste what you copied into the Find what, Replace all with nothing to work,
I now see the last character in each cell is a "non-breaking space" and if i go into each cell and manually delete the last character everything works fine.
Is the a way to do that for a column at a time.