None of this makes any sense, you were either shoplifting or not. I'm guessing not due to them gifting you a £50 voucher... 
If they still believe you were acting in a dishonest way they wouldn't give you a £50 voucher.
I can't help but think you are making some of this up but I can't for the life of me understand why?

If they still believe you were acting in a dishonest way they wouldn't give you a £50 voucher.

I can't help but think you are making some of this up but I can't for the life of me understand why?