20% off code added to restaurant deal.
Get to checkout page and log into PayPal, click payment and strange page comes up saying there is an error.
Click 'back and try again. Same error.
So click back again and amount still says '-20%'
So I click 'pay by card' fill in and payment accepted.
Only receipt says the original amount (No 20% off applied)
So I go to the live chat and he says I've got 3 orders. First 2 pending because payment didn't occur and the third time the code wasn't applied because I used it the first time and it's a one time code 
He said he can't refund me as they Don't do part refunds
But as a good will feature he will credit me £4.60
So basically they say '20% off but then don't take it off then only credit you the amount so you have to spend with them again??