It's all very well and good to reiterate the conventional wisdom that a tax refund means you've made an interest-free loan to the government. We know that.
We also know that it's a simple matter to transfer funds from a savings account (back) into a checking account—which is what happens when the spendthrift uses automatic deductions from his or her checking account once or twice a month.
What you want to do, if you suffer from financial "impulsivity,"* is open a savings account that is in a different bank from where you do your checking. It should be across town from you, and inconvenient to your bank. They should keep old-fashioned bankers' hours, and you don't want a debit card that's linked to it, either.
* The real word is "implusiveness," but apparently people who work in psychiatry or psychology like to use a different word, so we'll know that they are "one of the club." It's reminiscent of attorneys substituting "which" for "that"—the usage may be wrong, but it marks them as part of an (illiterate) elite.