Issues with vendors can lead to problems within your business. You need to try to resolve them quickly and in a satisfactory manner.
Regardless of what the problem is, you should strive to open the lines of communication.
Address the issue
You need to be upfront and clear about the problem and the resolution you want. It is imperative not to allow problems to linger because the vendor may start to think you do not care. Once something happens that is not agreeable, you need to step up and speak out.
You should be open to negotiating a solution. Keep in mind that the vendor may have something going on that is beyond their control. Supply chain issues or the unavailability of certain goods could be the reason why your vendor is not delivering. This may be something they cannot change. So, you need to be open to hearing them out and working together to reach a solution.
Know when to move on
If you are communicating and the vendor is not responding or there are serious issues where the vendor is simply not willing to abide by your contract, then it may be time to move forward with litigation. You may have no choice but to go to court to force a resolution with the vendor and solve the problem.
Ideally, you will be able to resolve any issues with vendors between you and them. But sometimes, that is not possible. You may have to accept that going to court is the only way to solve what is going wrong.