Recharged air conditioner Compressor rapidly clicking off and on

Ac was not cooling I went to Pepboys for check up
the ac and the check up guy told me need to
Recharge Ferron is low system needs to be flushed
and recharge. I agreed. BTW Compress was a year
old. They recharged the system and I took the car
drove less than 5 miles when I stopped the car I
hear compressor clicking off and on  every 10-15
seconds and Car was vibrating. Went back to
Pepboys guy said leave the car. When I left car
running and ac on I heard a Big Bang noise and
smoke.

Next day they said relay was bad we changed it and
it does when temp is high 80's.

Took the car but it was doing the same clicking
rapidly off and on back to Pepboys.

Now Pepboys is saying I need to replace the
compressor. They filled the Ferron too much and
damaged Ac system or compressor?

I asked Pepboys to fix it no charge but they to
refund the recharge fee only. How do I convince
them to fix it.