Weather King - A bunch of *******

I had purchased a voucher from Daddy Deal for a car air conditioning regas service at Weather King Durban as my car underwent some mechanical repairs where the air conditioning pipes from the compressor had to be removed. Took my car in to regas the air conditioning system. The car wasn't cooling like how it was originally. Took it back after 2 weeks as requested for a leak test as requested and I told the guys the car isn't cooling like how it originally was. They plugged their machine onto my car and checked for 'leaks'. They claimed to have put in 450g of gas originally and only 120g came off from the car. No leaks were detected at the time. The tech jacked up my car twice and went looking at the underneath with his glasses and light not sure what's he looking for as there's no air conditioning pipes running under the engine and my car has covers underneath. The manager recons I must pay him R590 for gasing the car again or buy another voucher for R300 from Daddy's Deals. I asked him to show me how is the 450g gas topped up into the car which he claims the machine did it but couldn't provide any proof. At no point did they mention any additional charges during the check of their leak test. There's absolutely NO transparency in their workmanship. Furthermore I found out that my 2011 BMW E90 takes 580g of gas. These guys are just *******. Daddys Deals vouchers at R300 and your own in house charge is R590. I wouldn't go back to these ******* and wouldn't recommend anyone else to use them either.