Never happened to me but as a locksmith I've seen it many times.
"Cracking" safes isn't my specialty but I've done it many times. To do so without ruining the safe is highly specialized and takes special tools and equipment not to mention know how. Each brand is different. You can't just start drilling holes and hope for the best. And depending on how the safe is made, it can be time consuming and noisy.
There is an automatic safe dialer that mounts to the safe magnetically. Plug it in and turn it on and it will dial every combination possible until the safe opens. There is also a tool that will do the same for electronic locks. And some locksmiths and safe technicians specialize in safe lock manipulation where they can figure out the combination by using a special method which again is not easy and takes time.
These tools are not easily obtained and are expensive.
So.........My last concern with my safe is someone gaining entry with finesse. Every safe that I have seen that was broken into or attempted to be broken into was done with brute force. Most petty thieves lack the knowledge and don't carry special tools with them. And they would have to know ahead of time that you indeed have a safe and whether or not your safe was worth the time to break into at the risk of getting caught.
With high quality heavy duty safes I have seen attempted entry with pry bars, torches, gas operated saws, sledge hammers, dragging it down the street with a chain wrapped around it, and other petty methods. With some of the safes the damage was minimal and others had to be replaced.
With low quality safes I have seen them easily pried open or smashed open with a sledge hammer. I've even done so myself.
I've been called several times by local law enforcement to give my opinion as to how a safe was stolen or broken into. I have also opened several safes for them to obtain evidence that could be used against bad guys.
It is my opinion that a perspective safe buyer should buy a decent quality safe. Not a big box store safe. Generally the big box store safes are economy models that look high quality but are not. They are bought cheap and sold for more than they're worth. Some of these safes are branded with names that we associate with and know well. Don't fall for it. However, if all you can afford is a big box store safe and can't save the money for a good quality safe then buy what you can. At least your guns will be somewhat protected. The most common problem that I have seen with these low quality safes is workmanship. They fall apart or quit working locking the owner out. Sometimes they are under warranty and sometimes not. And some owners have to jump through a million hoops during the warranty process.
There are other considerations when buying a safe such as size, weight, and the presence of dogs or an alarm system. But if your safe quits working or falls apart ask yourself how mad you will be at yourself for not buying a better one.
