Sometimes the fact that you can't change it is a great feature. Obviously if it's missing a critical feature, then you are screwed, but often these requests for

Sometimes the fact that you can't change it is a great feature. Obviously if it's missing a critical feature, then you are screwed, but often these requests for customization are made because it seems like they are quick and cheap to make and it will be automated and free after a one-time cost. However, having a whole team of engineers run your billing department is a lot more expensive than hiring someone in finance ops who can do a manual refund or spend an extra 5 minutes every quarter dealing with anniversary billing. Especially if you are B2B, you are going to run into that huge client that wants to be billed net 37 on the lunar calendar, and it's better to get someone in finance to send invoices if necessary each week than to calculate moon phases in your product.