Splitting the $100 dollar voucher with 50% offer on phone | 7-Eleven Rates and Plans | Consumer forum

My local 7-11 will not let me get 4x $25 vouchers and then get the 50% off the phone. I received the same response on the last 2 years November specials. Yet they were able to do it at a different store. I think they overide the computer some how.
Could someone check their receipt and explain exactly how it was punched into the cash register? I will then bring the instructions to my local clerk. thanks.