Since you are recording audio, make sure you are in a silent place or a place with minimum background noise. This will help you create a perfect business voicemail greeting clear.
Some phone systems require the recording to be on a mp3 or wav file, and some you just have to record the greeting right into your phone. This last way is likely one you have tried already. Use the link here to find a FREE voicemail greetings for business. These are scripts you can modify for your use.

(make a little noise in the background). Hi, you’ve reached your friend’s house. He/she isn’t home right now and I took the opportunity to rob it. I was about to steal the machine as well and you called. After the beep, leave your name and number. I will write it on a post-it and leave it on the refrigerator for him/her to see. Oh and one more thing; where did you say you lived?
While email and text support saw an increase in recent years, many customers, partners, and potential hires still prefer to call your company directly. When writing your voicemail script, include basic information such as a short greeting, your company name, an invitation to leave a short message, and the time frame in which the caller can expect a return call. If relevant, you may want to include your office hours, extensions for company departments, and the contact information for your office manager or HR department.