Google Play refund - Where's my money at?!

I paid for a monthly subscription via Google Play for £6.99. I decide to up my subscription the following month to £10, but didn't cancel the £6.99. I requested a refund off the 'seller' and they issued a refund straight away.

The money is showing as having been refunded (hopefully a screenshot will have been provided showing what is showing on my Google Play account). However, I have no idea where the money is as it has not found its way into my bank or even Google Play accounts.

Any ideas where the pennies are and how I can go about getting them back. The 'seller' is saying they don't know what happens once a refund has been actioned at their end, and Google Play information is as understandable to me as Swahili.

Any help would be greatly appreciated!