How can you find your debit cards PIN if lost your PIN?

The only way to get it - is to contact the card issuer, and ask them for a new PIN. For security reasons (a) they won't tell you the existing PIN over the phone and (b) won't issue the same PIN through the post - in case someone has stolen the card and is 'pretending' to be you.

Once the company sends out a new PIN - you cna change it so something more memorable.