There is a single Haldex Pump on your Cupra
Ateca, located at the front of the car up by the gearbox.
Looks like
Haldexrepairs.co.uk offer a comprehensive kit, although query the Fill & Drain bolts for the Cupra
Ateca.
Useful Blog post from Awesomegti.com;-
Haldex Servicing - Why and when?
When I enquired with my Main
Dealer last year, I was advised the
Service Interval on the Haldex Pump is every three years (30K miles?). Cost £149.
Hope this helps.