More empty cylinders

I replaced two Sodastream 30lit cylinders at the PicknPay at Ashburton recently, Got home, no prize for guessing-empty! Both of them! Had an empty one few months ago, also swopped at same place. So, I have lost more than R300 now, plus the travelling, plus the inconvenience. I called their assistance line the last time to ask where I else I could replace cylinders reliably, That question was never answered, Instead, it was pointed out to me that using a Sodastream was far less costly than buying bottled carbonated drinks. Well guess what, I have now wasted too much on Sodastream products with NO value. Got 1x 60L and four x 30L cylinders. Talk about a fruitless exercise. If I approach Sodastream again, l should have proof that I am telling the truth, right? Well, this is one product deficiency one cannot prove! Sodastream are in the perfect position, virtually unassailable! I am so upset, I honestly have to refrain from hurling profanity at them. If I do not get a decent response from them by 1 Jan 2016, I am going to put an angle grinder to the cylinders, and destroy both the Sodastream dispensers. It would not be fair to inflict such junk on the SPCA.