So so so so so so disappointed in Brights

I was so excited puting my inverter in lay buy at brights blackheath,,,but the problems started actually that very day.When they told me,should the price increase of the new stock then i would have to pay the price difference. But to my understanding the price can't change because item was purchased at price advertised on shop floor.Ok so we agreed the price is going to stay as is,faithfully i payed my lay buy,but on the day of collection i was informed they don't have stock,which again according to me they should have kept the item.Because technically the item is sold,unless i dont keep my end of the paymet agreement which is three months,only then they are within their right to sell it.So now they dont have my item and wanna sell me a more or less similar inverter for much more then the one i lay buyed.And on top of that,should i want my money back, they going to charge me a 1% fee for i don't know what (which they later said its fine they wont, like they doing me a favor) But now I'm still begging for my money,everytime i phone I'm informed they will het back to me in 5 minutes,its been half a day and still no feed back. I'm really disappointed, and to be honest i use to buy every single peace of hardware equipment with them tools paints etc. But as of this day,I vow not to buy even a nail from them........I know my money wont make a difrence in your coffers, but be sure to know that you've just lost a valuable contributor to it.............