Hi,
You have a very decent QA/Dev ratio. Quality assurance should not be a problem with such team. I'm sure you only need the best practices, tips and advices, especially on Testing Strategy and handling user feedback.
We offer experienced QA consulting (over 10 years of experience) for 3 hours ($100/hour).
During this period of time 3 Milestones are going to be achieved:
1. Issues identification 1h
2. Mitigation plan (creating Test Strategy) 1h
3. Retrospection and next steps 1h
During this time, QA SME will understand your current problems, present improvement plan (attention to test cases creation), how to create a Test Strategy (share it with your client and encourage to contribute), provide the necessary guidelines for software development and quality control cooperation (early feedback about discovered defects) and customer satisfaction (transparent feedback about testing progress and results), provide advices on testing tools (test scenarios repository, tools used for mobile testing, test automation possibilities). Looks like your issue is regression testing as well.
Interested? We are waiting to help you;).