If you’re comfortable doing the recording in-house, but you aren’t sure how to put it all together, you could find a freelancer from a service like Upwork to handle this part for you. You’d select a freelancer to work with, provide them with your files and directions, and let them handle the rest.
You will most likely run into the typical Stalingrad-esque repeating messages that state how important your call is to the business. It is only slightly less annoying to have some form of default music that plays on a loop, and gives you the virtual experience of being stuck in an elevator, listening to muzak ad infinitum.

However, not all businesses who field customer service calls are entirely unsympathetic to your plight. Some choose to make your wait as pleasant as possible by poking fun at the situation.
Unfortunately, it gets worse. Due to general sloppiness when it comes to setting the volume level for music on hold, a form of distortion known as “clipping” can appear, and regularly does if you’re willing to believe personal anecdotal evidence. If you want to know about the science behind clipping, then Wikipedia will tell you everything you need to know, but for those of us who have things to get on with, we can get by just knowing that when something is played too loud down a phone line, the sound starts to distort and sound really horrible.