Fed up

So I got discounted vouchers for registering for Zando's news letter, I did my shopping and entered the voucher as given and for some reason the card payment took time to process and the app eventually said time out, meaning my payment didn't go through. When I tried paying again and tried using the voucher again it said to me the voucher can just be used once, but my point is how because technically I didn't use the order as it didn't go through, okay I make peace with it, I downloaded the app and used the app's first time user voucher and guess what it did the same this time only because I had to increase my online purchase daily limit. So why exactly do you give us those voucher if you literally don't want us to make use of it. I tried purchasing the as the price was and I went through with the payment even confirmed it on my bank app and everything and I later get an email says my payment didn't go through with an unclear reason, I mean there is money in the card so why didn't it go through....... One of the item was R299 and hmmm today it is back on R499 so do you guys really expect me to purchase the item

I don't think I will ever support Zando in anyway, and will definitely encourage people around me not to