In December I had an appointment for testing with Check2fly on Saturday evening, before a flight on Sunday evening.
On Saturday afternoon, about 30 hours before my flight, I received an SMS that my appointment was cancelled. No reason was given. Online rebooking for my flight was not possible and no customer service was available. It was quite a scramble to find an alternative at such a short notice.
Check2fly didn't even bother to refund the payment.