I had a Rheem 2 ton 12.4 Seer Condensor #RAMB024, with R22 refrigerant installed 11 years ago.

The compressor fan died, and the tech came out and told me it would be best to change the outdoor compressor, he inspected the inside coils and said that the air handler was fine.

There was no mention of loss of efficiency, upgrade of refrigerant, or incompatability of any type.

They installed a RUUD 13AJN Series Condensing Unit 13 SEER.
Then did a retrofit of the expansion valve.

Within 24 hours the coils had frozen over, they came out and worked on it again, and later that night, the coils had frozen over again. Finally two days later, they came to realize they had installed a 1.5 ton valve instead of a 2 ton valve. They came back out and replaced it. Since then, the ac has been running from 9am to 4am non stop, it often didn't even achieve the thermostat temps, being 1 -2 degrees warmer than what was set. When I received my electric bill last month. Comparing apples to apples usage vs. temp, the system is running 20%+ higher than the old one.

They came out again, said the refrigerant was low, and that the Rheem air handler's fan needs to be sped up to distribute the air throughout the house, they adjusted it upwards but said that it may not even be enough to achieve the 20 degree split they were looking for. When they arrived it was only 10, before he left he said that it was up to 15, but that they would continue to work on it.

The AC is set to 78 day, 76 at night, all of the windows have Insulated curtains which are drawn day and night (am living in a bat cave), the blinds on the first floor are closed just to achieve a little coolness.

The last tech essentially said you need to change the air handler.
I'm not working now, so there is no more money for this repair.

Can they ever get it to work properly? Or should I just cut my losses and have them refund my money.