Terrible service from McDonalds

I am extremely disappointed in the service that I have received from the McDonlds at Beacon Isle. There has been numerous occasions where their ice cream machine is not working. On 20/01/2020 I wanted the 3 for 2 deal on the McFlurry’s, they entered two voucher codes and both never worked, the cashier then called her manger and explained what had happened, the manager then mentioned that their ice cream machine was not working, once again. I am frustrated at the fact that the cashier never told me that before telling me to redeem my vouchers. Something needs to be done about the service one receives from this branch.