Can I make tenant pay for service call on HVAC issue in Georgia

[CYndilyn J.]

Tenant made a maintenance request that HVAC was not working properly upstairs. HVAC contractor checked it out and said the unit was working properly.  The fee was $99.00 soI charged tenant the fee.  Tenant says HVAC still is not working properly so tenant contacted another HVAC contractor to come look at unit.  They found the unit had not been cleaned (dirt caked up on coils and the unit was low in freon indicating there is a leak in the system.  Owners do not know when the unit was last serviced.  The tenant was told by their HVAC contractor another part of the problem is the unit is 1/2 ton too small to cool the square footage of home.  He recommended an in duct blower fan to be installed to move the air flow throughout the home.  Our payment system is set up so that any fees added to the tenants account in addition to the rent each month must be paid in full to include the rent.  In other words, our tenants must pay the amount showing in the payment portal or nothing.  The tenant chose to pay nothing because they are disputing having to pay the service call fee saying it is the "owners responsibility" to keep up the HVAC unit and make sure it works properly.  They said they will pay the rent by mail from here forward instead of through the payment portal.  I do not feel it is the owners responsibility to pay the service fee being the service technician determined the unit was "working properly" at that time.  The tenants have lived in the home for 7 months.   Rent is due on the 1st and late after the 5th day of the month and they have always paid within the grace period since moving in.   My question is do I have any grounds to evict them?  Suggestions on how to handle.

Thank you!