Unfortunately, there's not much you can do. Lenders aren't required to report data to the credit bureaus. It's completely voluntary. You can always request that they report the information, but they aren't legally obligated to do so.
When you're shopping for a loan, it's always a good idea to ask lenders if they report to the three major credit reporting agencies. This is especially important when you're working with a credit union. While credit unions usually have better interest rates than big banks, some don't report data to the credit bureaus and others will only report to one of the three major credit bureaus. This is something to keep in mind the next time you apply for a loan with a credit union.