As consumers increasingly use subscription-based services, there is a rising tendency to discontinue a service to try others, due to a larger variety of options available. This incentive has prompted the widespread use of dark patterns by companies aiming to make the termination of their services more difficult for users by creating overly complicated cancellation processes. An excessive number of steps, confusing options, and unclear wording are among the tactics used to complicate these processes. To gain insight in this phenomena, this study aims to create knowledge about the effectiveness of various dark patterns within the category of Interface interference, with a particular focus on their ability to mislead users in a cancellation process, and their subsequent impacts on usability and user experience. Using a mixed-methods approach, the study engages user testing with a website prototype to provide an understanding of the different categories of dark patterns' effects on usability and user experience. The findings indicate that the dark pattern categories False hierarchy and Trick question resulted in the most pronounced negative reactions and led to most deviations in the prototype interaction data, signifying a severe impact on usability and experience. Additionally, the categories Hidden information and Preselection, while not provoking as many immediate reactions, were frequently overlooked by users. This observation underscores their potential as concealed manipulative agents, misleading users in a subtler manner.