I generated a one time card to purchase clothing from M&S online. I returned several items and this is when all the problems began. I have had to jump hoops to prove the returns by providing receipt numbers, screenshots of the online orders and returns information. All the dates of the orders and returns correctly aligned with the Klarna app. The app did not submit for the final return, so I again sent screenshots of the online order and the return via email. Klarna has stated I missed the deadline, which is incorrect, as I emailed them as soon as the app would not submit. Klarna sent 2 different reference numbers for the dispute, which do not even match the M&S order number. This company tries to put the onus on the customer and treats them unfairly. Very poor company and terrible customer service. Its one- time card is obviously not compatible with M&S orders and returns or Klarna is otherwise completely incompetent.The dispute resolution team respond with absolutely non- sensical advice. I have repeated myself numerous times in emails and they get picked up by different people responding to what has already been said previously and this has resulted in me sending the same screenshots of proof of return over and over again. Terrible service!