Speedy Midrand: ********* Practices and lack of customer service!!!

I am utterly disgusted at the ********* practice of your organisation, and this is why. I contacted Speedy on the 11th of April and requested a quote for 2 tyres for my Mazda Mx5, (205/45/R17). (2 Cheapest Bridgestone tyres as you are the specialists in those Brands) A staff member had given me a quote for a 2 Bridgestone tyres at R1500 each, which I accepted. Due to the tyre being punctured, and unable to drive and I was not well, I requested that they change the tyres at my home about 3km away from your organisation. I went to speedy, paid for the tyres, I was assured by the guy at the counter that they were bridgestones, as all I received was the cash sale slip from the speedpoint. They followed me home, jacked up the car and took away the tyres. When they came back with the new tyres, my partner was outside, and checked if they put the tyre in properly (He doesn’t know brands of tyres). I then flew out to Cape Town, arrived on Friday night, (I have proof of travel) and when I got to my car on Saturday morning, I realised that they were some local brand fitted and not the brand that was promised. I then went to google the tyre to check the price, and is about R900 - R1100 a tyre. I subsequently called the guy, he apologised, and said he will get me my promised tyres. I called him again that sat afternoon, and he is still busy trying to find the tyres, and I must drive around with the car, and he will sort it out. I then had called him on the 18th and 19th of April, and he said he will call me back at 2pm. I called several times, and have emailed many times over (I have a call log and email proof). I then contacted the owner, who asked me to speak to the guy that sold me the tyre. The guys denies quoting me on a bridgestone, as said I requested a quote for the cheapest tyre. If I wanted any cheap tyre, Why would I pay R1500 per tyre at Speedy, when I could have got the same tyre or any other tyre, cheaper anywhere else. I must be crazy for paying R 400 - R600 more for a tyre at Speedy if I was looking for any cheap tyre. You can probably call most of the tyre places in Midrand, they would tell you I called them asking them for a quote on tyres. They all offered me cheaper brands of tyres. Their story of the cheaper brand doesn't make any sense. I asked for the cheapest Bridgestone tyre!! (Please note that Bridgestone Potenzas are about R1500 - R1600 a tyre at least). So it makes sense for me to believe I was getting Bridgestones for that amount. All I asking is for Speedy to be ethical about their practices. Your calls are not recorded, and we live in trust that you honour what you quote us or fit onto our cars. I am really upset about this, and hope that Speedy would remediate this urgently. An appalled Customer!!