Looking to enter a Experimental Psychology for Human Factors program and could use some advice

Here's the situation I'm in:

B.S. in Psychology

Minor in Business Management

3.0 GPA

I've been graduated and in the workforce for about 4 years now and my work experience is limited to managing outside sales for large companies in multi-state territories.

I have zero research experience or experience directly related to the application of psychology beyond how I use it during my sales meetings.

The program I want to get into is not going to admit me with my current CV right now. My plan as of now is to get my Masters in Business Administration (due to family I'm stuck in my city, and counseling masters are my only options besides the MBA) and then look to transfer into the doctorate program. The way I see it I've either got to retake undergrad courses to raise my GPA or do very well in a masters program. Might as well get the MBA so if I don't get admitted, I'll have more than an improved GPA to show off.

I also lack letters of recommendation, I initially wasn't going to do grad school and didn't get them at the time. At this point the recommendation that I could get from one of my profs really wouldn't be that great. Here is my idea that I think may be unfeasible...

The first company I worked for was terribly inefficient in managing their communication of information between the sales team, customer service, and repair centers. There were hours in each day that could have been saved with some very simple measures. The company spends a lot on the products but not much on organizing the sales force, not to mention terrible training programs. I'm talking 'here print some powerpoint slides that I made 15 years ago that really just consists of bullet points despite having access to information that I could collate into something useable.'

My idea is to approach the human resources director, whom I was on good terms with before leaving, and ask if I can work on solving some of these problems that really only require an investment of time. It's a lot of work on the front end and they were never willing to pay someone to do it. I'm offering it for free.

I want to focus on team dynamics and learning so after doing some of the more simple portions I'd like to work my way into that for them. I just really need some research or applied experience and I don't know how else to get it. Despite being a multinational well known company I was able to know the President relatively well. Ideally I'd like to get a great letter of recommendation from him and the company HR director. I'd be doing my masters then too so obviously that's a source.

My girlfriend seriously doubts a company, even one I worked for, would let someone come in and seriously entertain the thought of using someone in this capacity. The way I see it, my free time for the last five years has been primarily reading, writing, and studying various topics, I would enjoy the hell out of focusing that into a project like that.

... so what do you guys think?