The client is responsible for creating an accurate description of the work expected at the start. Whilst, of course, if the client believes that the work is not in line with their expectations, they have the right to request amendments to any work don. However, if they are increasing the workload, I would suggest that it is reasonable grounds for raising a dispute. Upwork has to work on a level of 'fair-play' and if your client is unwilling to accept your professional recommendations and implementations in the project then they are using the wrong medium to get their work done. It seems that your client needs to be informed that the work expected of you has been fulfilled to your own professional standards, that can be justified by other sources. If they are not happy with this, they should pay you for your work and go elsewhere.
