So I had a 10% for £750 spend which is fine automatically applied. I had a 10% discount code works online, instore didn’t work. I showed them proof it worked online and asked for a screenshot to show head office which I did and they approved it. after leaving the store they called to say I owed them £164.90. So I should have had 20% off looking at the invoice/order details page they added an extra 10% so I got 30% off Hope it’s clear now

what happened is i had a 10% automatically apply when i spent ofer £750 then 10% voucher code. but what the guys did was not realise the 10% was already applied automatically on their system then applied it again. So they have made a mistake but keep ringing me to pay. the weird thing is they don't mention the word mistake, they say you owe us/ have an outstanding balance to pay. how would i say paid under protest to the bank or at the store when paying? i belive i would need proof

Hi I purchased a TV bed recently from Dreams, I paid a few hundred £ in cash and did the remaining amount on finance. On the website and in store where a 10% of £750 was and I provided them with a discount code. The code didn’t work in store but worked online. I showed them proof of this via email and on my phone as well. I completed the finance procedure, I was provided the order details via print out physically to me. Later about 1hrs time after placing the order in store, I was called to say there was an outstanding balance of £164.90. (They did not mention mistake they just said outstanding balance) Firstly I was completely shocked and secondly looking at the order details it is evident that they have added an extra 10% off my order. 2 people were with me when I was ordering (from the store) and none of them noticed the error. They have already done a credit search. They are not going to deliver the item unless I pay. As they have made a mistake, any thoughts on this should I pay or not?