service stinks

Received an sms stating if I open an acc I will receive a 100 voucher I replyed yes a guy phones open the acc stating I will receive a 100 unconditional voucher I must go to a store to activate the acc by making a purchase.get to the store they say u can't used it on sale item so I said its an unconditional voucher as I was told I didn't use it now I receive a message saying don't forget to use ur voucher exp 30 march 2015 go to the store to use it they say its expired already I called the customer service they say it still valid go back the store says its expired.the sales person at the markhams at the reds mall pta says he knows noting about the voucher all he knows that he knock off at 7pm that's poor customer service.they must not sell false advertisment to customers and waste our time.laid a complaint with their customer care said a lady by the name of tamlan nel will contact me 2 weeks didn't hear from her ever<br>