Infinity Nation Business Development interview questions

The interview process was as normal as others I had attended, I had my interview with the Client Services Director & Founder. After the interview I was told I would hear back from them within 24 hours, unfortunately, that wasn't the case so I had to chase the recruitment agency regarding the outcome of the interview. I was told I'd been unsuccessful because I was unable to demonstrate more complex selling of there product and cross-selling different services. To be frank there wasn't an opportunity for me to do this and how can I demonstrate this in an initial interview without knowing the companies offering or how they go about there sales process?