Vinted complaint: Customer service

I bought a pair of shoes, couldn’t wear as too narrow. Agreed with seller to send it back. Pressed ‘ I have an issue ‘, which did not work. Wrote to customer service, notified them but reply from Vinted was not helpful.

Notified Vinted again, explained that item is being returned, pressed yet again ‘I have an issue’ which yet again did not work. Kept customer service constantly informed, never received constructive reply and help. At no time did they stop the transaction, just told me that I should wait for their reply, which never came. In meantime, I posted returning receipt, asking them not to pay the seller…but they did anyway!!!!
All the above happened from 7th February – receiving the shoes and 9th February 23 sending it back.
Their final reply……I didn’t press ‘I have an issue ‘ and not dealing with it within 2 days !!!!

I expect compensation from Vinted for their incompetence, not unreasonable.