Bad service from suzuki Bloemfontein

I drive a suzuki swift and last month my car gave me a gearbox problem. I took it to suzuki in Bloemfontein but before that i ordered a clutch with them did a quote and paid them upfront before i take my car in for a clutch replacement. Over the phone i explained to them what is the problem and they asked if im sure the problem is the clutch and i said yes. Then i took the car in. Afterwards i received a call from the mananger my the name of Monti and asked me to come in and i did that. The guy explained to me that they gonna have to diagnose the car 1st to be certain if the problem is the clutch. He explained the diagnosing fee very well and i understood very well i had no problem with it. They did that and they called me Afterwards and they told me that the proble is not a clutch, my gearbox is ****ed up there's some broken metals inside the gearbox. To fix it they will need between R30 000 to R35 000 estimation price. I told them i dont have such amount of money i cant afford to pay such amount. They refunded me the money back however they deducted the diagnosing fee of R1 100 some couple of rands. Of which i didn't have a problem with it. I towed my car somewhere end i explained to them i have a problem with a gearbox i didn't tell them what is the problem i wanted them to find the problem and see if they will tell me the same story that they told me at the dealership. They called me 2 days after and they told me problem is the clutch they recommend me to change the whole clutch kit. I asked them if is there any broken metals inside there gearbox and if the gearbox is ****ed up.? They said they will check again and get back to me... they checked and gearbox was still ok. I gave them a go ahead to change the clutch kit and i paid them R7 800. Now my problem is at suzuki their diagnose was incorrect but i paid for it. I was not treated fairly by suzuki Bloemfontein and i think they wanted to over charge me for nothing. The TCF outcomes were not followed here. I also think they wanted to **** me to pay R30 000 just for clutch kit. Im not happy with the diagnosing fee that i paid because whatever that they diagnosed is incorrect... i ask them if they see these to kindly pay back my diagnosing fee back because they cant do their job and as a client it was unfair for me to pay for that.