I was sold a lie, Boss Auto Spares is very ********* and they rip people off

I searched their website for a clutch kit which was priced at R2500. I went there to but the part and was told its out of stock, but i can pay for it and i will get it the next day. I then paid for it (R2500). I called them the next day to check if it had arrived and i was told yes. I went there to collect and then to my surprise, i was told the price had increased to +/-R3500 or so. The guy then said he can give it to me for R3000. Mind you the website price is still R2500 at this time. Out of desperation, i paid the R500 difference. I then found a cheaper clutch then decided to return this one (the next day) with other spare part that were incorrect. With all of this said, i understand they have their policies and one of them states that you will be charged a 20% handling fee for correctly provided parts. But what surprises me is the description of the part on the 1st invoice is not the same as whats on the second invoice (with R3000). How do i know for sure that they provided me with the correct part? I was then told my refund will be processed on Monday. Now i am the one who must constantly call and follow up on my refund and i am being taken from pillar to post. Boss Auto Spares is a ******* and they dont know what they are doing. I will never ever in my life buy from them and i regret recommending to my friends.