This means that the original payment failed (usually this is due to CVV code being incorrect or the Billing Zip/Post Code not matching the banks records)
Your own bank have held the funds in case we re-apply for the funds directly after this using the correct CVV code (had you followed up with the payment directly after) however due to the elapsed time if you paid for this order now a new payment would most likely be taken rather than applying to retake the original payment from your bank.
Essentially the reason is, your bank have authorised us to take the money despite the CVV / Post Code mismatch (some banks will allow this for online transactions from secure retailers using mainstream payment gateways such as ours using stripe) However our anti-fraud checks of CVV and Zip Code required to meet valid PCI compliance have failed and so we have chosen not to take funds despite your bank giving us permission to take the funds. This is as we feel that in the interests of fraud prevention CVV and Post Code verifications should not fail.
Different banks vary but usually your bank will release these funds in a maximum of 2-3 days once they're happy that the payment will not be re-applied for using the correct code on the original transaction reference. Many banks release the funds later the same day.
I hope this helps you to understand. You may contact your bank and request they release these funds sooner, some banks are happy to do this.