Rats are ruining my business?

I think your best solution would be a few of those electronic rodent repellers. Although they advertise pests, they are not much on the bugs, but they will work with any rodents or marsupials.
They simply annoy rodents to pack up and leave babies and all. They do work, no poisons or dead rodents to bother with.
My small business, I also had some personal stored items, and no problem until a catering company moved into the same building, and that brought in the roof rats in numbers. Destructive little vermine or would have paid them no mind.
A few of those electronic devices and no more problems.

There has to be an entry point for them to get in, they can squeeze through a half inch gap, get professional help to seal the gaps.

I also heard they hate the smell of ferrets so if you know someone who owns one you can put some used bedding or rags to where the rats come in.

Rats hate feminine smells.like perfume scented candles flowers they like rotten smell so either clean up your act or someone to.get your business floor smell of flowers and your rubbish out wipe all surfaces and leave talcum powder on the floor to see their footprints where they are coming and going and get Bob.

For sure use a cat just make sure to keep up with the rabies vaccine

You could defiantly adopt a cat! But maybe if you want a cat that you don't want to bond with, many farms sell/give away "barn cats". You could look into those. Good luck!

Yes a cat could help tremendously, but you have to be ready to care for a pet and provide the cat with all that it needs.

We had a mice infestation and while our two cats killed around 70 mice throughout the year, the mice really stopped when we hired someone to seal all entrance points. They have tools like copper mesh or steel wool that will stop rodents.

It will probably help but is not guaranteed to eliminate the rats. You need better traps and to find out where the rats are getting in and block it up. Not all cats hunt. You won't know if the cat you get is a hunter until you try it out.