Whenever any gun malfunctions, which happens way more than you might think, I advise determining specifically what is causing the issue before sending it in. Without some help they may shoot it and it works fine for them, so they do not do anything and send it back. For example, does it do it with all types of shells? Or, hopefully, it may be some small issue you could remedy yourself. If it starts doing it again I would get someone experienced to help me diagnose the problem.
What could have happened... did.