Tenants having stove issues

[Derly Augustin]

I'm a new landlord, I have a tenant who has always had issues with the stove. When they first moved in I put a brain new Frigidaire stove glass top in, a few weeks later they called me to tell me the top is cracked, since it still had a warranty the manufacturer fixed it. A week later the same thing happened again it was fixed I'm pretty sure this happened a 3rd time. That's when I decided to switch them to coil top and get rid of that glass top.  Now that they have a coil top whirlpool electric range I thought it would be over,(not at all) now they are calling to tell me it does not get hot enough to cook, I sent a technician out twice, he said there is nothing he can do that's the way these ranges are. Any ideas, I want them to be satisfied but at the same time, this stove issue is frustrating... After all, appliances can be costly...