Frausted and disappointed, with uber eats, **** promo

Was given a promo code by uber eats to use for discounts on take out , my 1st attempt with McDonalds was a failed attempt although it showed me the amount to pay after the discount was added it still deducted the full amount from my account, luckily I was able to cancel and get refunded immediately , I was then given another code to apologize for the cancelled order i think it's a standard option that is sent out and when trying to use that code it did the very same thing again with the 2nd order but this time it did not cancel the order, I was charged the full amount , tried to call McDonald's In Chatsworth Center and there was no answer , I then called the driver and informed him that I cancelled the order even before they started to prepare it , he said ok and then rocked up with the delivery a short while later and said that the store cant do anything about it and he was told to just deliver it, they cant do anything else to help me .being ****ed off and fraustrated I sent a number of emails and , even before he came I kept trying to cancel the order again and again or get some assistance and sent emails but to no avail as up till today I have not recieved a response from uber eats or McDonald's as they should be responsible as well because they are using the service ..its flippen ridiculous and frustrating when u expect to use something that promises u an option but does the opposite, especially if a person is working on a budget and calculating the discount amount you then decide to go for it and only having to be charged the full amount , in that case I would not even bothered to use the promo or the codes ..wasted my time following the process , searching the app , using the app just to be ****med...its just way to attract us to use the app and get **** to