I'm having more or less the same problem. Let me just mention the core points:
1) My A/C wasn't turning on so I stopped using it for 1 year or so.
2) I recently went to Bashir Autos at Tariq Road and they suggested a long list of repairs like blower servicing, fan switch servicing, a/c button, coil and bla bla bla. They said that all that might cost you around 5000-8000. and that's a lot to spend on my 2003 cultus. So I walked away from there.
3) I went to another a/c wala and he just topped up gas in my a/c there was already some gas in there left from last year). Then he did some wiring and stuff as my car's rpm weren't increasing after a/c was turned on. At that time it all seemed fine. I paid 1500 and left.
The Problem: My a/c switch does not turn on and off when I want. When I start the car, turn on blower and press a/c switch, the a/c starts but when I try to turn it off, it just keeps on running. I try pressing the a/c button hundreds of times but it doesn't turn off. In between drives, sometimes it turns off on its own but that happens very rarely. It just keeps on all the time. So I end up turning off the blower but I still feel that compressor is still working because the car feels heavy.
Is this an A/C button problem or because of faulty wiring or what? TIA