Begin replying to “thank you” with one of the two phrases, as appropriate
“From each according to their ability!” (if you helped with something you are particularly good at)
“To each according to their needs!” (you are doing something that would be condescending to say the other person couldn't do, but you still helped anyway. customer service reps and cashiers can say this instead of “have it your way”)
I genuinely do not mean this as a joke. If you are already willing to fall on your sword, I propose this.