DSTV Unreliable ******

I purchased an explora decoder that comes with installation online on the DSTV website and paid via my credit card but they never sent me a proof of payment for the decoder and the decoder was not delivered on time. on Frustration last month I then bought another decoder that comes with installation and paid on the website using my credit card, However on delivery they delivered two standard decoders without installation and I couldn't follow-up because there was no proof of payment sent by DSTV and the agent that tried to assist me could not locate the purchase, I also didn't get any indication as to when the decoder will be delivered. When the delivery took place lastweek there were two decoders and both were without installation. When I tried to follow-up via the installation agent, they could not assist me because there was no proof of purchase and there was no voucher given.