We are sorry to hear you have not had great success requesting for product reviews or seller feedback! A part of the challenge is that there is not a one size fits all with regards to asking for reviews or feedback, and messages have to be continually optimized until a good formula is reached.
It is always recommended to analyze your message subject line and content to make changes if you see that your customer base is not responding well. We have a great series revolving around who should be asking for reviews or feedback, when and how. Some of the first articles in the series are below:
We would be happy to help make sure your messages are Amazon compliant (it’s free!). Feel free to choose a time that works best for you from SellerLabs.com/schedule.