Question about responding to tenant threatening to withhold rent

[Taha Tekreeti]

I manage my own property in Virginia, and my tenant asked me to replace the oven because it's burning food. I asked for measurements to arrange the replacement, but they took two weeks to respond. When they finally sent the measurements, they also listed other repairs. I was busy and didn’t reply immediately, and now they’re saying they’ll withhold rent until I address their requests. How should I respond without seeming like I'm only replying because of their threat?