Horrible management and service

So I go to Wetton Debonairs to redeem my voucher I've won as partaking in voting for a soccer team on the app. The lady at the counter says she needs a manager and comes back and tells me the manager is on his way after about 5 minutes the Steers manager comes to help ...I explain to him I've never used a voucher before and I don't really know how it works he looks as clueless as I am and trys to help anyway ...at this point all Debonairs staff disappear to the kitchen and no one is there to help the person waiting to order at the counter or this clueless steers manager who doesn't know what's going on eventually he calls a lady that's casually dressed from the back of shop and she starts saying you need to activate the voucher so he asks her how and she says press redeem now I don't know how stupid she thinks he is but we've been pressing redeem for the past 20 minutes so no my sister comes in very irritated and she asks why we haven't ordered yet, I tell her that they also don't know how to redeem the voucher ...she then asks for a Debonairs manager and they say there is no manager in store and that the steers manager is there to assist so now I ask who the other lady was thinking she must probably own the shop but they tell me she is also a manager so now we ask for contact details of some higher person and they tell us they refuse to give any information so now we ask how they don't know how there own app works the lady at the counter says they don't have a menu they still waiting on one now I'm furious because what the hell is she even saying??? We can literally see menus everywhere then miraculously this lady comes out of the blue and claims to be Debonairs manager she explains that the app apparently doesn't work in there store and that they waiting on feedback as to why and what the problem is so now ive lost it and I tell that after a whole half an hour of struggling with *********** people that the whole store has a problem yet they lead me on to believe I could redeem my voucher for a whole half an hour so we start arguing and they start shouting back saying that other peoples vouchers have worked before but this is a first I tell her that she just told me they have problems with the app and they waiting on feedback now she's saying this is the first problem she now tells me that my phone is the problem ...This is my last visit to Debonairs ...Staff is rude and ***********.