Vodabucks daily shake *******!

Vodabucks is a complete *******. I powered my way to puzzle pieces for almost all the prizes. Then suddenly as I got to needing only one puzzle piece on all of them I get the message "sorry you have already collected that piece". This has now been happening for over a week. So basically the algorithm is set up to only hand out set number of prizes per month and it is pure luck whether you get one and has nothing to do how many vodabucks you spend on the daily shake. Not cool Vodacom!!!