My guess if it's a chargeback on a credit card?! then...
Bank have refunded you for the whole transaction (presuming you brought more than one item in the transaction, sorry I don't know the history of your issue) and now claiming the money off the retailer/supplier.
As I've worked for various retailers I've been on the receiving end of this a couple of times. The retailer only has a set period (normally a couple of weeks I think though it's been a while so I can't remember) to contest this, so as not to be out of pocket, but unless there's a really good reason with evidence provided to not refund the consumer the retailer is screwed. I understood it that this stage happens before the chargeback actually is credited into the consumers account so suspect you're good to go.
Would presume the retailer is in a bit of a shambles and has bigger fish/debts to deal with so you'll be good to go.
Just sit on it for 3 months.
EDIT: Oh here you go
and from Barclays bank for business
You're given 14 days from the date of the chargeback request to respond to it and provide relevant proof and information, as set and regulated by the Card Scheme.
We'll do everything possible to defend chargeback requests that we receive, on your behalf. However, specific time limits and rules applied to each chargeback in line with the Card Scheme, greatly influence the actions we are able to take.
If the Card Scheme rules were breached, the transaction amount may be charged back to your business and debited from your account. However, if the transaction wasn't in breach, we may be able to defend the chargeback.