Started trading as a shop on May 25th, had a lot of transactions in the first day, a number of customers have emailed us to say they paid via paypal express and have been sent a refund on June 25th.
A lot of customers have been upfront and honest and resent the money back, however we still have a bit of a hole of missing money.
When I look at the orders of affected customers on shopify, there is no indication of any refund being sent or the transaction not being processed. There is no sign in PayPal of the money ever entering my account and then being returned so there is no record of who has or has not been affected.
Is there any way to see a trial of payment and find out who needs to be contacted?
It sounds like PayPal issued the refunds, not Shopify. You may need to contact PayPal about this issue.
Did you create a brand new PayPal account to link to your store when you set it up, in order to collect PayPal payments? If it was a brand new PayPal account, and you suddenly received numerous payments but did not go into PayPal to confirm shipping, etc. of the orders, PayPal might have flagged them and refunded the money. I'm not aware of them doing this in any other case, but I know they watch new accounts very closely for potential signs of fraud until you have established a history on the account.