H1B in rfe- in US - changed my role from developer to tester - issues?


I work for a service based company A with Client B , in US for past 6 months. My h1b expired sep 30, 2014 and I applied extension. Now VISa is in rfe., asking end-client letter. I was a computer programmer(developer) when I applied extension, now my role has become SQA(tester). So when I approached my client for a letter, they are not willing to provide End-client letter with designation as Comp programmer. In this case, what should i do?

Is it eligible to apply a fresh extension with changed roles and responsibilities, leaving this Visa petition extension on hold?

Please adivise.

Thank you for the response.