emergency gone greedy

i took my puppy in for a case of rat poisoning on Sunday morning. asked about vitamin k and was told i do not need it as it will cause a false negative in a blood test i need to have done in 3 days time. i told them i will have the blood test done at my ordinary vet in 3 days time my vet informs me that if the ppt test is positive it is actually to late and a blood transfusion will then need to be done. So they just want you to come back with a sicker dog in 3 days time. to make more money of from you.