I am sure you have asked this before - I have certainly answered it before, but it was worded slightly differently then.
Unfortunately, this time you have omitted to include a vital piece of information and without it there are an infinite number of possible answers.
You should have said that the bank transposed the pounds and pence. eg. If the original cheque was for �12.34, the bank gave you �34.12 (this is not the answer).