Amazon’s attorneys have been accused of playing tricks to hinder the Federal Trade Commission’s (FTC) investigation into its Prime service, according to a recent court filing. The FTC claims that the attorneys deliberately slowed down the inquiry, almost causing investigators to overlook crucial documents.

The FTC’s allegations were revealed in a 92-page amended complaint filed on Wednesday. The lawsuit, which has been ongoing for three months, accuses Amazon of intentionally making it excessively challenging for customers to cancel their $14.99-per-month Prime subscription, which offers free delivery and other benefits.