Booked a Transavia flight (using booking.com ) from Amsterdam to Malaga. Today (2 days before departure) I got an email from "Gotogate in partnership with Booking.com" telling me that my flight would leave at the same time, but would be on GetJet airline.

My concerns are as follows:
When I booked with booking,com, I did not know they were in partnership with Gotogate, or would have booked directly on Transavia site, having read warnings about using third party booking sites, especially Gotogate.
I have never heard of GetJet, and after getting the notice have read several poor reviews about the airline.

What are my consumer rights in these circumstance?
Any advice appreciated.