I think the key is to get them to germinate then keep them in the sun light but cool. I know our house never gets above 21oc so might have an effect on the growth of the plants.
I don't know what the temp is like in your country but I am guessing it is hotter than mine, maybe try to keep them a little cooler.
Last year I popped my strawberry seedlings in the greenhouse and then next day they were crisp from the sun and died. so maybe a cooler place to keep them would help you too.
The compost I use is called clover, and it is a peat mix compost very fine texture and from what my anti has told me should be a lot more money than what I pay for it.
good luck with the next ones you try to sow, I hope that you get some good results.