I had visited this business in person many times years ago. Some pen refills I recently ordered online were not working well. A phone call was all that was needed to get an apology and fix the problem. Good service is something that you don't often get these days. They will see to it you are treated well!
P.S. This is the brand of mini refill you will want for top quality. More money than the no-name refills from China, but you will get something worth using.