ABTA policy here:
https://www.abta.com/news/coronavirus-outbreak
Shearings policy here (which complies with the ABTA one):
https://www.shearings.com/help/covid19
Most travel operators are providing credit notes (in the form of eVouchers, etc) in respect of cancelled travel. e.g. Eurostar are providing me an eVoucher to the value of the trip to Paris I had booked in three weeks time.
In common with nearly all travel firms, there's a 'force majeure' provision within Shearing's contractual terms, which almost certainly relieves them of their normal responsibility to provide you with a refund (rather than a credit note) under the current circumstances:
https://s3-eu-west-1.amazonaws.com/test.uat.images.shearings/docs/default-source/2019/holiday-info.pdf?sfvrsn=a4f9e085_2
(See Section 10 of the Trading Charter)
So it seems likely that you'll have to either book another holiday now (at a 10% discount) or accept a credit note and book another holiday (at the regular price) later on.
However if they've actually charged you twice for a single booking then, clearly, you're still entitled to a refund of the unauthorised payment. (Contact your bank or credit card provider for advice).